THE CONDITIONALS

What are conditionals in English grammar? Sometimes we call them 'if clauses'. They describe the result of something that might happen (in the present or future) or might have happened but didn't (in the past) . They are made using different English verb tenses.

The Zero Conditional: 0

FORM: if + present simple, ... present simple

USAGE: It refers to actions and facts that are irrefutable. You can use 'if' or 'when' with no change in meaning.

If you heat water to 100 degrees, it boils. (Condition; boiled water, consequence: it boils)

Water turns to ice if you freeze it. Water turns to ice when you freeze it (Condition: freeze water, consequence: ice)

There are three types of the if-clauses.

type	condition
1	(If I study, I will pass the exams)
2	condition in theory possible to fulfill (If I studied I would pass the exams)
3	condition not possible to fulfill (too late) (If I had studied, I would have passed the exams

The First Conditional: 1

FORM: if + present simple, ... will + infinitive

('Will' can be replaced by a modal verb. E.g. may, might, can should, must)

USAGE: This talks about a 'real' situation in the future that is possible, probable or even certain, once the condition has been satisfied.

if clause	main clause
Simple Present	will-future or infinitive or Modal + infinitive

Examples

If I study,	I will pass the exams.
If you see John tonight,	tell him I'll e-mail him.
If Ben gets up early,	he can catch the bus.

The if-clause can be at the beginning or at the end of the sentence.

If I study,	I will pass the exams.
I will pass the exams	if I study.

If it rains tomorrow, we'll go to the cinema. (Condition: if it rains, consequence: we'll go to the cinema.

If he studies hard, he will pass the exam. (Condition: hard study, consequence: passing the exam.

She might buy it if she has enough money. (Condition: having enough money: possible consequence: buying it)

The Second Conditional: 2

FORM: if + past simple, ... would, could, might + infinitive

(When the verb 'to be' is used in the if clause it can be 'if I was' or 'if I were'. The latter is more formal.)

USAGE: Communicates a present or future 'unreal', hypothetical situation that is presently not true and is unlikely ever to be true.

if clause	main clause
Simple Past	would + infinitive or could+ infinitive or might + infinitive

Examples

If I studied,	Iwould pass the exams.
If I studied,	I could pass the exams.
If I studied,	I might pass the exams.

The if-clause can be at the beginning or at the end of the sentence.

If I studied, I would pass the exams.
I would pass the exams if I studied.

If I won the lottery, I would travel the world.

If I had a time machine, I could go back to the dark ages.

If I had a lot of money, I might buy an island in Scotland.

The Third Conditional: 3

FORM:if + past perfect, ... would, could, might + have + past participle)

USAGE: Refers to a hypothetical past action (or non-action) and the hypothetical past consequence/result. As the 'action' was purely hypothetical, the condition could never have been satisfied, and subsequently the consequence is or was impossible.

if clause	main clause
Past Perfect	would +have + past participle or could + have + past participle or might + have + past participle

Examples

If I had studied,	I would have passed the exams.
If I had studied,	I could have passed the exams.
If I had studied,	I might have passedthe exams.

The if-clause can be at the beginning or at the end of the sentence.

If I had studied,	I would have passed the exams.
I would have passed the exams	if I had studied.

If I had practiced the piano, I would have been better. (but I didn't practice the piano)

She would have been angry if she had seen me. (but she didn't see me!)

If I had gone to bed early, I would have caught the train.

Examples (affirmative and negative sentences)

type		Examples
		long forms	short/contracted forms
1	+	If I study, I will pass the exam.	If I study, I'll pass the exam.
1	-	If I study, I will not fail the exam. If I do not study, I will fail the exam.	If I study, I won't fail the exam. If I don't study, I'll fail the exam.
2	+	If I studied, I would pass the exam.	If I studied, I'd pass the exam.
2	-	If I studied, I would not fail the exam. If I did not study, I would fail the exam.	If I studied, I wouldn't fail the exam. If I didn't study, I'd fail the exam.
3	+	If I had studied, I would have passed the exam.	If I'd studied, I'd have passed the exam.
3	-	If I had studied, I would not have failed the exam. If I had not studied, I would have failed the exam.	If I'd studied, I wouldn't have failed the exam. If I hadn't studied, I'd have failed the exam.

MIXED CONDITIONAL

We sometimes combine a second conditional clause with a third conditional clause.This is most commonly formed as follows:

If + past perfect, would + infinitive

If I had listened to him, I would be in serious trouble now. (I didn't listen to him, so I'm not in trouble!)

This mix refers to a hypothetical past action or state, and the hypothetical present consequence. Many other mixes, though not so common, are possible.