Section 4. Grammar Reference
1. THE Article
Indefinite — a, an
Uses
· Before a singular noun which is countable when it is mentioned for the first time and represents no particular person or thing.
"A horse is a noble animal."
· Before a singular countable noun which is used as an example of a class of things.
"A book is something you read."
· With a noun complement, including names of professions.
"She is a doctor, he became a famous actor."
· In expressions of price, speed, ratio.
"60 miles an hour, 4 hours a day, 30p a box"
· With "few" and "little"
"a few people, a little sugar"
· In exclamations before singular, countable nouns. "What a pity! What a sunny day!"
· It can be placed before Mr., Mrs, Miss, Ms + surname.
"a Mr. Brown phoned today."
Not Used
· Before names of meals except when preceded by an adjective.
"We had a late breakfast and decided to miss lunch."
Definite — the
Uses
· Before nouns of which there is only one.
"The earth is round."
· Before a noun which has become definite as a result of being mentioned a second time.
"We saw a good film last night. It was the film you recommended."
· Before a noun made definite by the addition of a phrase or clause.
"The woman dressed in black."
· Before a noun which, by reason of locality, can represent only one particular thing.
"There’s a bee in the kitchen."
· Before superlatives and "first", "second" and "only"
"The longest river in the world."
· Before singular nouns used to represent a class of objects.
"The donkey is a very obstinate animal."
· Before an adjective used to represent a class of persons.
"That tax hurts the rich."
· Before names of seas, rivers, chains of mountains, groups of islands and plural names of countries.
"the Pacific Ocean, the Thames, the Andes, the West Indies, the Netherlands"
Not Used
· Before countries, towns, proper names.
"Charlie lived in Chicago in America"
· Before parts of the body and articles of clothing — these normally prefer a possessive adjective.
"Lift your left arm."
"He removed his hat."
2. THE NOUN
Plurals of Countable and Uncountable Nouns
The plural form of most nouns is created simply by adding the letter s.
snake = snakes
ski = skis
Barrymore = Barrymores
Words that end in -ch, x, s or s-like sounds, however, will require an -es for the plural:
witch = witches
box = boxes
gas = gases
bus = buses
kiss = kisses
Jones = Joneses
There are several nouns that have irregular plural forms.
child = children
woman = women
man = men
person = people
goose = geese
mouse = mice
barracks = barracks
deer = deer
And there are nouns that maintain their Latin or Greek form in the plural.
nucleus = nuclei
syllabus = syllabi
focus = foci
fungus = fungi
cactus = cacti (cactuses is acceptable)
thesis = theses
crisis = crises
phenomenon = phenomena
index = indices (indexes is acceptable)
appendix = appendices (appendixes is acceptable)
criterion = criteria
A handful of nouns appear to be plural in form but take a singular verb:
The news is bad.
Gymnastics is fun to watch.
Economics/mathematics/statistics is said to be difficult.
Numerical expressions are usually singular, but can be plural if the individuals within a numerical group are acting individually:
Fifty thousand dollars is a lot of money.
One-half of the faculty is retiring this summer.
One-half of the faculty have doctorates.
Fifty percent of the students have voted already.
And another handful of nouns might seem to be singular in nature but take a plural form and always use a plural verb:
My pants are torn. (Nowadays you will sometimes see this word as a singular "pant" [meaning one pair of pants] especially in clothing ads, but most writers would regard that as an affectation.)
Her scissors were stolen.
The glasses have slipped down his nose again.
Plural Compound Nouns
Compound words create special problems when we need to pluralize them. As a general rule, the element within the compound that word that is pluralized will receive the plural -s, but it's not always that simple. Daughters-in-law follows the general rule, but cupfuls does not.
Special Cases
With words that end in a consonant and y, you'll need to change y to i and add -es.
baby = babies
gallery = galleries
reality = realities
This rule does not apply to proper nouns:
more than one Kennedy = Kennedys
Words that end in o create special problems.
potato = potatoes
hero = heroes
. . . however . . .
memo = memos
cello = cellos
. . . and for words where another vowel comes before the o . . .
stereo = stereos
Plurals of words that end in -f or -fe usually change the f sound to a v sound and add --s or -es.
knife = knives
leaf = leaves
hoof = hooves
life = lives
self = selves
elf = elves
There are, however, exceptions:
dwarf = dwarfs
roof = roofs
I General Rule
The Possessive Case is formed by adding ’s (the apostrophe s) or only ’ (the apostrophe) to the noun denoting a living being.
II Ways of Pronunciation
III Some Particular Cases of Spelling, Pronunciation and Use
1) Sometimes ’s may refer to a whole group of words. In this case ’s is added to the final element.
E.g. Jane and Mary’s room
Inspector Megre’s pipe
George Bush’s wife
Note: If the word group is too long to be followed by “ ’s “, the preposition “ of “ is used instead.
E.g. What is the name of the man who lent us the money?
(
What is the man who lent us the money’s name?
)
2) After a plural noun ending in -s /-es only « ’» is used E.g. The girls’ father
But : If a plural noun does not end in –s /-es we use “ ‘s “ in the possessive case.
E.g. The children’s father
3) If a noun (a proper noun as a rule) ends in -s which is not an inflexion we use either form
(“ ‘s “ is more common). However, it does not influence the pronunciation.
4) Note that we say:
a woman’s hat = a hat for a woman a boy’s name = a name for a boy
a bird’s egg = an egg laid by a bird
a children’s book = a book for children, etc.
IV Use of Possessive Case with Lifeless Things
For things, ideas, etc. we normally use “of”
E.g. the roof of the garage (
the garage’s roof
) the name of the book (
the book’s name
)
the owner of the restaurant (
the restaurant’s owner
)
Sometimes we can use the structure “noun + noun” E.g. the garage door
the restaurant owner
However “ ’s “ is often used:
1) for an organization ( =a group of people)
E.g. the government’s decision
the company’s success
2) a) for a place where man lives or works
E.g. I like to dine at my aunt’s
We buy pills and tablets at the chemist’s (the baker’s, butcher’s, grocer’s, tobacconist’s)
b) for some other places
E.g. St. Paul’s (Cathedral) St. James’s (Park)
3) with nouns expressing:
a) time
E.g. Have you still got yesterday’s newspaper ? Next week’s meeting has been cancelled.
(today’s, tomorrow’s, this evening’s, Monday’s, last year’s, etc.)
b) periods of time
E.g. a day’s wait
I’ve got a week’s holiday starting on Monday. Jill has got three weeks’ holiday.
I live near the station – it’s only about ten minutes’ walk.
1. THE Adjective / Adverb
The Degrees of Comparison in English grammar are made with the Adjective and Adverb words to show how big or small, high or low, more or less, many or few, etc., of the qualities, numbers and positions of the nouns (persons, things and places) in comparison to the others mentioned in the other part of a sentence or expression.
An Adjective is a word which qualifies (shows how big, small, great, many, few, etc.) a noun or a pronoun is in a sentence.
An adjective can be attributive (comes before a noun) or predicative (comes in the predicate part):
e.g. He is a tall man. (‘tall’ — adjective – attributive)
This man is tall. (‘tall’ — adjective – predicative)
An Adverb is a word which adds to the meaning of the main verb (how it is done, when it is done, etc.) of a sentence or expression.
It normally ends with ‘ly’, but there are some adverbs that are without ‘ly’:
e.g. She ate her lunch quickly. He speaks clearly. They type fast.
There are three degrees of comparison of adjectives.
1. The positive degree is used when simply describing persons or things.
e.g. The atis tree is tall.
Anita is young.
Chicos are expensive.
Carlo is intelligent.
2. The comparative degree is used when comparing two person or things.
e.g. The ipil-ipil tree is taller than the atis tree.
Josephine is younger than Anita.
Mangoes are more expensive than chicos.
Alex is more intelligent than Carlo.
Rule!
* The Comparative degree of adjectives with one or two syllables is formed by adding -er.
e.g. brighter, louder, nearer, narrower, funnier
* The comparative degree of adjective with two or more syllables is formed by adding more before the adjective.
e.g. more obedient, more comforable, more responsible, more studious, more industrious.
Note that the word than follows the comparative form.
e.g. Celia is prettier than Doris.
Water is more refreshing than juice.
3. The superlative degree is used when comparing three or more persons or things.
e.g. The acacia tree is the tallest of all them.
Irene is the youngest of them all.
Grapes are the most expensive of the three.
Eric is the most intelligent of the three.
Rule:
* The superlative degree of adjectives is formed by adding -est to the adjective.
e.g. longest, thinnest, loudest, highest, darkest
* The superlative degree of adjective with two or more syllables is formed by adding most before the adjective.
e.g. most courteous, most beautiful, most intelligent
The article the preceded the superlative form.
e.g. Dado runs the fastest.
Christy is the most responsible person in the class.
Adverbs , like adjectives, have three degrees of comparison – the positive, the comparative and the superlative. The different degrees of comparison are formed in different ways:
Short adverbs having just one syllable form the comparative and the superlative by the addition of –er and –est to the positive.
Hard (positive), harder (comparative), hardest (superlative)
Soon – sooner – soonest
Fast – faster – fastest
Late – later – latest
Loud – louder – loudest
Clean – cleaner – cleanest
Clear – clearer – clearest
Low – lower – lowest
High – higher – highest
Note that almost all adverbs which are also used as adjectives belong to this class.
Adverbs which end in –ly take more for the comparative and most for the superlative.
Softly (positive), more softly (comparative), most softly (superlative)
Happily - more happily - most happily
Swiftly - more swiftly - most swiftly
Truly - more truly - most truly
Greedily - more greedily - most greedily
Efficiently - more efficiently - most efficiently
Certainly - more certainly - most certainly
Painfully - more painfully - most painfully
Joyfully - more joyfully - most joyfully
Exception
The adverb early is an exception to this rule.
Early (positive), earlier (comparative), earliest (superlative)
Some adverbs form their comparative and superlative degrees in an irregular manner:
Far (positive), farther, further (comparative), farthest, furthest (superlative)
Late (positive), later (comparative), last, latest (superlative)
Well (positive), better (comparative), best (superlative)
Badly (positive), worse (comparative) , worst (superlative)
Little (positive), less (comparative), least (superlative)
Much (positive), more (comparative), most (superlative)
Notes
It should be noted that only adverbs of time, degree and manner have three degrees of comparison.
Adverbs such as now, then, once, there, where, why, how, not, never, ever etc., cannot be compared and hence they do not have the three degrees of comparison.
2. THE PRONOUN
A pronoun is a word that substitutes a noun or noun phrase. There are a number of different kinds of pronouns in English.
Types of pronouns:
1 Demonstrative Pronouns - this, that, these, those.
They substitute nouns when the nouns they replace can be understood from the context. They also indicate whether they are replacing singular or plural words and give the location of the object.
e.g. You take these bags and I'll take those. - ("Those" refers to bags that are at a distance from the speaker.)
e.g. We bought this last year - ("This" refers to something that is sing., near the speaker and readily understood in the context of the conversation.)
2 Personal Pronouns- I, you, he, she, it, we and they are the subject personal pronouns used in English. They are used to substitute the names of the people or things that perform actions. In English, we make no distinction between singular and plural forms of "you".
e.g. She took the bus last night. (She substitutes the name of the person who took the bus.)
Me, you, him, her, it, us and them are the object personal pronouns used in English. They are used to substitute the names of the people or things that are affected by an action.
e.g. John took it. (It substitutes the name of the thing that John took.)
3 Possessive Pronouns - mine, hers, its, ours, theirs are used to substitute a noun and to show possession or ownership.
e.g. This is your disk and that's mine. (Mine substitutes the word disk and shows that it belongs to me.)
4 Reflexive Pronouns - myself, herself, itself, ourselves, yourselves, themselves are used when the complement of the verb is the same as the subject.
e.g. He shot himself.
The reflexive pronoun can also be used to give more emphasis to the subject or object.
e.g. I did it myself. (I want to emphasise the fact that I did it.)
e.g. They spoke to the Director herself. (Emphasising the importance of the Director)
5 Interrogative Pronouns - who, what, where, etc..
A Wh- question word, when it acts as a pronoun substituting the person or thing being asked about, is an interrogative pronoun:
e.g. What is her phone number?
e.g. Who is in charge?
6 Negative Pronouns - nothing, no, nobody, etc..
A negative pronoun refers to a negative noun phrase; no-one, nobody, neither, none and nothing are the negative pronouns used in English.
7 Reciprocal pronouns - each other, etc..
Phrases like 'each other' or 'one another' are reciprocal pronouns. They show that an action is two-way:
Jane and Helen greeted each other. (this means that Jane greeted Helen and Helen greeted Jane)
8 Relative Clause - who, whose, which, that, etc..
Relative pronouns, such as That, Who, Which, Whose and Whom can be used to introduce clauses in sentences:
The woman who interviewed me was very friendly.
I can't stand dogs that bark loudly.
9 Quantifier - some, any, something, much, many, little, etc.
A quantifier, as its name implies, expresses quantity. Quantifiers can be a single word or a phrase and are used with nouns. They can be used with both a countable or an uncountable noun to express amount or quantity.
Some, much, many, few, little, a lot, half, three , etc., are common quantifiers.
10 Indefinite Pronouns - anyone, somebody, one, all, etc
An indefinite pronoun refers to unspecified people, things, places, etc.
e.g. Anyone can tell you.
Someone took it.
Nothing was done to help the victims.
Many tried, but few succeeded.
The numeral is a word that denotes an abstract number or the abstract numerical order of objects; it can be a noun, an adjective or a pronoun.
The questions they answer are: how many? how much? which?
Irrespective of their morphological status, numerals are invariable, e.g.
Ten multiplied by two is twenty (noun);
Ten students left by bus (adjective);
Not all the students were present, ten had left earlier (pronoun);
The first (student) asked whether to stay or to leave (pronoun/ noun)
Numerals can be classed according to various criteria, e.g.
1) according to form:
a) simple: one, two, three, nine, ten, eleven etc.
b) compound: twenty two, fifty one etc.
c) by derivation: thirteen, fourteen, thirty, sixty and all the ordinal numeral etc.
2) according to content:
a) cardinal numerals
b) ordinal numerals
c) fractional numerals
d) multiplicative numerals
e) distributive numerals
f) adverbial numerals of recurrence
1. Cardinal numerals
a) cardinal numerals show the number of objects:
1 one 10 ten
2 two 20 twenty
3 three 30 thirty
4 four 40 forty
5 five 50 fifty
6 six 60 sixty
7 seven 70 seventy
8 eight 80 eighty
9 nine 90 ninety
10 ten 100 one hundred
11 eleven 1,000 one thousand
12 twelve 1,000,000 one million
13 thirteen 1,000,000,000 one billion
14 fourteen
15 fifteen
16 sixteen
17 seventeen
18 eighteen
19 nineteen
How to use the cardinal numeral:
- numerals hundred, thousand, million, billion do not get a plural suffix when used with numbers, e.g. 3,000 = three thousand, 5,000,000 = five million; however when used to show an indefinite number, they are used in the plural , e.g. thousands and thousands of people, tens of millions of books etc.
- use and before the tens, e.g. 1,157 is read one thousand one hundred and fifty seven; 3,004 reads three thousand and four etc.
- a comma (,) is used instead of a full stop (.) to separate millions from hundreds of thousands, thousands from hundreds, e.g. 3,457,908 etc. and a full stop (.) instead of a comma (,) in decimal fractions, e.g. 5.7; 234.987 etc.
- years are read as follows: the first two figures together and the last two together, e.g. 1991 = nineteen ninety one; 1809 = eighteen oh nine; starting with 2000 the years are read as follows: 2000 = two thousand; normally for the first nine years of each century oh[ou] is used to express 0 (zero), but exceptionally for the first decade of the 21st century and is used to express 0 (zero) so 2001 is read two thousand and one etc.
2. Ordinal numerals
the first the second
the third the fourth
the fifth etc.
Except the first three ordinal numerals whose form is different, the others are formed from the cardinal numeral, and all are preceded by the.
Uses:
telling the date: the date may be written in various ways, but it is read as follows: the + the numeral + of + name of the month and then the year, e.g. June, 4th , 2000 = the fourth of June, two thousand etc.
to show regular intervals, e.g. every third week = o data la trei saptamani, twice every second week etc.
3. Fractional numerals
- common fractions: 2/3 = two thirds; ¼ =one fourth; 4/6 = four sixths; ½ half; 3 ½ = three and a half etc.
- decimal fractions: special attention should be paid to the fact that instead of comma in the European system, a full stop/a period is used in the Anglo-Saxon system, e.g. 5.6; 3.56; 2.8765; 1.2 etc.
4. Multiplicative numerals
Show how many times a quantity or number increases, e.g.
double
twice
threefold
fourfold
The form is an ordinal numeral + –fold.
5. Distributive numerals
These numerals show the distribution and grouping of objects:
(one) by one
by twos
by threes
4. Adverbial numeral of recurrence
Shows how many times an action is repeated or how many times a quantity or number is larger/smaller than another quantity or number, e.g.
once
twice, two times
three times, thrice
four times
once and a half
three times a year
many times
5. THE VERB
A verb is a word, or a group of words, which describe an action or a state.
Four Verb Forms
The inflections (endings) of English verb forms are not difficult to remember. There are only four basic forms. Instead of forming complex tense forms with endings, English uses auxiliary verb forms. English does not even have a proper ending for future forms; instead, we use auxiliaries such as "I am going to read this afternoon." or "I will read." or even "I am reading this book tomorrow." It would be useful, however, to learn these four basic forms of verb construction.
Infinitive |
Base form |
Past form |
Present participle |
Past participle |
to work |
I work. I can work. |
I worked. |
I am working. |
I have worked. |
to write |
I write. I can write. |
I wrote. |
I am writing. |
I have written. |
Simple Tenses
Present Simple
We use the Present Simple to talk about actions we see as long term or permanent. It is a very common tense. Here, we are talking about regular actions or events.
They drive to the office every day.
He doesn't come here every day.
The news usually starts at 8.00 P.M.
Do you usually have porridge and eggs for breakfast?
Here, we are talking about facts.
Water freezes at 0° C or 32° F.
What does his dead-pan expression mean?
The Tsna flows through Tambov.
Here, we are talking about future facts, usually found in a timetable or a chart.
Christmas Day falls on a Monday this year.
The plane leaves at 6.00 tomorrow morning.
The working day doesn't start at 5.00.
Here, we are talking about our thoughts and feelings at the time of speaking. Although these feelings can be short-term, we use the present simple and not the present continuous.
They don't ever agree with us.
I think you are right. He doesn't want you to do it.
Past Simple
We use the Past Simple to talk about actions and states which we see as completed in the past.
We can use it to talk about a specific point in time.
She came back last Monday.
I saw them in the street.
It can also be used to talk about a period of time.
She lived in London for five years.
They were in New York from Monday to Thursday of last week.
When I was living in St. Petersburg, I went to all the art exhibitions
I could.
You will often find the past simple used with time expressions such as these:
Yesterday ● three weeks ago ● last year ● in 2009
● from May to July ● for a long time ● for 7 weeks
Future Simple
To be going to
There is no one 'future tense' in English. There are 4 future forms. The one which is used most often in spoken English is 'going to', not 'will'.
They're going to launch it next month.
I'm not going to talk for very long.
Notice that this plan does not have to be for the near future.
When I retire I'm going to go back to Barbados to live.
In ten years time, I'm going to be boss of my own successful company.
We use 'going to' when we want to make a prediction based on evidence we can see now.
Look out! That cup is going to fall off.
We can replace 'going to go' by 'going'.
They are going out later.
He's going to the exhibition tomorrow.
Will (shall)
Some people have been taught that 'will' is 'the future' in English. This is not correct. Sometimes when we talk about the future we cannot use 'will'. Sometimes when we use 'will' we are not talking about the future.
We can use 'will' to talk about future events we believe to be certain.
The sun will rise over there tomorrow morning.
Next year, I'll be 50.
That train will be late. It always is.
Often we add 'perhaps', 'maybe', 'probably', 'possibly' to make the belief less certain.
I'll probably come back later.
He'll possibly find out when he sees Jenny.
Maybe it will be OK.
Continuous Tenses
Present Continuous
The Present Continuous is used to talk about present situations which we see as short-term or temporary. In these examples, the action is taking place at the time of speaking.
Who is Bob talking to on the phone?
I'm not looking. My eyes are closed tightly.
In these examples, the action is true at the present time but we don't think it will be true in the long term.
I'm looking for a new separate apartment.
He's thinking about leaving his job.
They're considering making an appeal against the judgment.
In these examples, the action is at a definite point in the future and it has already been arranged.
I'm meeting him at 7.30 .
They aren't arriving until Sunday.
We are having a special dinner at a top restaurant for all the senior mana
-
gers. Isn't she coming to the dinner?
Past Continuous
We use the Past Continuous to talk about past events which went on for a period of time.
We use it when we want to emphasize the continuing process of an activity or the period of that activity. (If we just want to talk about the past event as a simple fact, we use the past simple.)
Were you expecting any visitors?
Sorry, were you having a rest?
I was just making some coffee.
I was thinking about him last night.
In the 1990s few people were using mobile phones.
We often use it to describe a "background action" when something else happened.
I was walking in the street when I suddenly saw him.
She was talking to me on the phone and it suddenly went dead.
They were still waiting for the bus when I spoke to them.
We were just talking about it before they arrived.
I was making a presentation in front of 100 people when the microphone stopped working.
Future Continuous
We use the Future Continuous to talk about future events which will go on for a period of time in the future.
We use it when we want to emphasize the continuing process of an activity or the period of that activity. (If we just want to talk about the future event as a simple fact, we use the future simple.)
Our work is not finished yet and we shall be working at this subject.
I shall be waiting for my friends at 6 o’clock tomorrow.
At nine o’clock in the morning tomorrow, Christina will be preparing the breakfast.
Kate will be waiting her friends at 5.
We often use it to describe a "background action" when something else will happen.
I will be doing my homework when he comes back.
She will be working when you come to see her.
He will be waiting for me when the train comes.
Peter will be listening to the radio when his mother returns home.
Perfect Tenses
Present Perfect
We use the Present Perfect when we want to look back from the present to the past.
We can use it to look back on the recent past.
I've broken my phone so I don't know what time it is.
We have cancelled the meeting.
He's taken my project. I don't have one.
When we look back on the recent past, we often use the words 'just', 'already' or the word 'yet' (in negatives and questions only).
They've already talked about that.
She hasn't arrived yet.
We've just done it.
We don't know yet.
Have they spoken to him yet?
It can also be used to look back on the more distant past.
We've been to Novgorod a lot over the last few years.
She's done this type of project many times before.
When we look back on the more distant past, we often use the words 'ever' (in questions) and 'never'.
Have you ever been to France?
Has he ever talked to you about the trouble?
I've never met Jim and Sally.
We've never considered investing in Pakistan.
Past Perfect
The Past Perfect refers to a time earlier than before now. It is used to make it clear that one event happened before another in the past. It does not matter which event is mentioned first - the tense makes it clear which one happened first.
John had gone out when I arrived in the office.
I had saved my document before the computer crashed.
When they arrived we had already started cooking.
He was very tired because he hadn't slept well.
'Just' is used with the past perfect to refer to an event that was only a short time earlier than before now, e.g.
The train had just left when I arrived at the station.
She had just left the room when the police arrived.
I had just put the washing out when it started to rain.
Future Perfect
The Future Perfect indicates that an action will have been completed (finished or "perfected") at some point in the future. This tense is formed with "will" plus "have" plus the past participle of the verb (which can be either regular or irregular in form):
I will have spent all my money by this time next year.
I will have run successfully in three marathons if I can finish this one.
By this time next week, I will have worked on this project for twenty days.
Before he sees his publisher, Charles will have finished four chapters in his new novel.
A Democratic president will have been in the White House for nearly half of the twentieth century.
How long will it have been since we were together?
Passive Voice
We use the active form to say what the subject does.
For example:
I speak English every day at work.
We use the passive form to say what happens to people and things, to say what is done to them.
For example:
English is spoken here.
We use the passive form when we don't know who did the action.
For example:
The car was damaged while it was parked on the street.
Personal and Impersonal Passive
Personal Passive simply means that the object of the active sentence becomes the subject of the passive sentence. So every verb that needs an object (transitive verb) can form a personal passive.
For xample: They build houses. – Houses are built.
Verbs without an object (intransitive verb) normally cannot form a personal passive sentence (as there is no object that can become the subject of the passive sentence). If you want to use an intransitive verb in passive voice, you need an impersonal construction – therefore this passive is called Impersonal Passive.
For xample: he says – it is said.
Impersonal Passive is not as common in English as in some other languages (e.g. German, Latin). In English, Impersonal Passive is only possible with verbs of perception (e.g. say, think, know).
For xample: They say that women live longer than men. – It is said that women live longer than men.
Although Impersonal Passive is possible here, Personal Passive is more common.
For xample: They say that women live longer than men. – Women are said to live longer than men.
The tense of a verb in the subordinate clause changes in accordance with the tense of the verb in the main clause.
The basic rules are as follows:
Rule 1
If the verb in the principal clause is in the present or the future tense, the verb in the subordinate clause may be in any tense, depending upon the sense to be expressed.
He says that he is fine.
He says that he was fine.
He says that he will be fine.
He will say that he is fine.
He will say that he was fine.
He will say that he will be fine.
Rule 2
If the tense in the principal clause is in the past tense, the tense in the subordinate clause will be in the corresponding past tense.
He said that he would come.
He told me that he had been ill.
I knew that he would not pass.
We noticed that the fan had stopped.
There are, nevertheless, a few exceptions to this rule.
A past tense in the main clause may be followed by a present tense in the subordinate clause when the subordinate clause expresses some universal truth.
Copernicus proved that the earth moves round the sun.
The teacher told us that honesty is the best policy.
He told me that the Hindus burn their dead.
A subordinate clause expressing place, reason or comparison may be in any tense, according to the sense to be expressed.
He didn’t get the job because his English isn’t good.
A fishing village once existed where now lies the city of Mumbai.
If the subordinate clause is an adjective clause, it may be in any tense as is required by the sense.
Yesterday I met a man who sells balloons.
Yesterday I met a man who sold me a balloon.
Rule 3
Note that when the subordinate clause is introduced by the conjunction of purpose that, the following rules are observed.
We use may in the subordinate clause when the main clause is in the present tense. We use might in the subordinate clause when the main clause is in the past tense.
I study that I may pass.
I will study that I may pass.
I studied that I might pass.
We eat that we may live.
He ate that he might not die.
Rule 4
If the principal clause is in the future tense, we do not use future tense in subordinating clauses beginning with when, until, before, after etc.
I will call you when dinner is ready. (NOT I will call you when dinner will be ready.)
I shall wait until you return. (NOT I shall wait until you will return.)
Rule 5
Expressions such as as if, if only, it is time and wish that are usually followed by past tenses.
I wish I was a bit taller.
It is time we started working.
He talks as if he knew everything.
We use reported speech when we are saying what other people say, think or believe.
He says he wants it.
We think you are right.
I believe he loves her.
Yesterday you said you didn't like it but now you do!
She told me he had asked her to marry him.
I told you she was ill.
We thought he was in Australia.
When we are reporting things in the present, future or present perfect we don't change the tense.
He thinks he loves her.
I'll tell her you are coming.
He has said he'll do it.
When we tell people what someone has said in the past, we generally make the tense 'more in the past'.
You look very nice. = I told him he looked very nice.
He's working in Siberia now. = She told me he was working in Siberia now.
Polly has bought a new car. = She said Polly had bought a new car.
Jo can't come for the weekend. = She said Jo couldn't come for the weekend.
Paul called and left a message. = He told me Paul had called and had left me a message.
I'll give you a hand. = He said he would give me a hand.
However, when we are reporting something that was said in the past but is still true, it is not obligatory to make the tense 'more in the past'. The choice is up to the speaker.
For example:
"The train doesn't stop here". He said the train doesn't stop here. He said the train didn't stop here.
"I like Sarah". She said she likes Sarah. She said she liked Sarah.
When we are reporting what was said, we sometimes have to change other words in the sentence.
We have to change the pronoun if we are reporting what someone else said. Compare these two sentences. In each case the person actually said "I don't want to go".
I said I didn't want to go.
Bill said he didn't want to go.
We have to change words referring to 'here and now' if we are reporting what was said in a different place or time.
Compare these two sentences. In each case the person actually said "I'll be there at ten tomorrow".
(If it is later the same day) He said he would be there at ten tomorrow.
(If it is the next day) He said he would be there at ten today.
Now compare these two sentences.
(If we are in a different place) He said he would be there tomorrow at ten.
(If we are in the place he is coming to) He said he would be here at ten tomorrow.