Conditional sentences

Conditional sentences

The conditional sentences are sometimes confusing for learners of English.

Watch out:

1) Which type of the conditional sentences is used?

2) Where is the if-clause (e.g. at the beginning or at the end of the conditional sentence)?

There are three types of the if-clauses.

type

I

condition

II

condition possible to fulfill

condition in theory possible to fulfill

III

condition not possible to fulfill (too late)

Form

type

if clause

I

main clause

Simple Present 

II

will-future (or Modal + infinitive)

Simple Past 

III

Past Perfect

would + infinitive *

would + have + past participle *

• We can substitute could or might for would ( should , may or must

are sometimes possible, too).

I would pass the exam.

I could pass the exam.

I might pass the exam.

I may pass the exam.

I should pass the exam.

I must pass the exam.

Examples (if-clause at the beginning)

type

if clause

I

main clause

If I study,

II

I will pass the exam.

If I studied,

III

I would pass the exam.

If I had studied,

I would have passed the exam.

Examples (if-clause at the end)

type

main clause

I

if-clause

I will pass the exam

II

if I study.

I would pass the exam

III

if I studied.

I would have passed the exam

if I had studied.

Examples (affirmative and negative sentences)

type

Examples

I

long forms

+

II

short/contracted forms

If I study, I will pass the exam.

-

+

If I study, I will not fail the exam. If I do not study, I will fail the exam.

If I study, I'll pass the exam.

If I study, I won't fail the exam. If I don't study, I'll fail the exam.

-

III

If I studied, I would pass the exam.

If I studied, I'd pass the exam.

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.

If I had studied, I would have passed the exam.

-

If I'd studied, I'd have passed the exam.

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.