If Clauses

TYPES
IF CLAUSE
MAIN CLAUSE

I
Future or present probable condition

+ present tense 
If I learn my vocabulary,

+ Present continuous (a present action or future arrangement)
+ Present perfect (a finished action)


If you’re looking for Tom,
If your documents are in order,
If you’ve finished the letter,



If you heat ice,

+ shall / will + verb 
I`ll get a good mark

+ can / may/ might (possibility)
+ may (permission)/can (permission or ability)
+ must/should or any expression of command, request or advice.
go upstairs.
You can/may leave at once.

I’ll post it.

+ Another present tense (automatic or habitual results)
It turns to water.

II
Future or present improbable condition

+ past tense
If I had a map,

+ past continuous

(we’re going by air and) I hate flying. If we were going by boat,



If anyone interrupted him,
Be → were for all the persons.
If I were you,

+ conditional tense (would + V) I would lend it to you.

+ might(possibility)/could(ability)
+ would/might be + V-ing

I’d feel much happier.

+ another past tense (wish to express automatic or habitual reactions in the past)
he got angry.


I’d take it.

III
Past unreal condition

+ Past perfect
If I had had time,



If we had found him earlier,

+ past perfect continuous
- I was wearing a seat belt. If I hadn’t been wearing one,

- (I was sitting in the back of the car) If he hadn’t been there,

+ Would have + pp
I’d have gone with you.

+ Could/might have + pp
we might have saved his life.

+ would have been + V-ing
I’d have been seriously injured.

I’d have been sitting in front.



If the first verb in a conditional If clause is should, were, had, we can leave out if and put the verb at the start of the sentence. Ex: Should any of this cost you anything, send me the billif any of this should..)
Were I in your shoes, I’d help her.(If I were in her shoes,…)
Had he been there, he’d have done it for you.(If he had been there, …)
If he were to resign, … = if he resigned… If I were to succeed, … = if I succeeded…

Should in the conditional clause has the effect of making it seem less likely that the condition will be fulfilled. It is possible to substitute by any chance for should, without changing the meaning.
Ex: If we should miss the train, we shan’t get there till after lunch.
(= if by any chance we miss….)


Conjunctions introducing conditional clauses
1. Unless + affirmative verb = If + negative
Ex: Unless you start at once, you’ll be late.
(If you don’t start at once, you’ll be late.)
Unless you had a permit, you couldn’t get a job.
(If you didn’t have a permit, you couldn’t get a job.)

2. But for = if it were not for/ if it hadn’t been for
Ex: My father pays fees. But for that I wouldn’t be here. (If my father didn’t pay fees, I wouldn’t be here.)
My father paid fees. But for that I wouldn’t have been there.
(If my father hadn’t paid fees, I wouldn’t have been there.)

3. Otherwise = if this doesn’t happen/ didn’t happen/ hadn’t happened
Ex: We must be back before midnight; otherwise we’ll be locked out. (If we aren’t back before midnight, we’ll be locked out.)
My father pays fees; otherwise I wouldn’t be here.
(If my father didn’t pay fees, I wouldn’t be here.)
My father paid fees; otherwise I wouldn’t have been there. (If my father hadn’t paid fees, I wouldn’t have been there.)

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