Conditional sentences
Conditional sentences are sometimes confusing for learners of English as a second language.
Watch out:
- Which type of conditional sentences is it?
- Where is the if-clause (e.g. at the beginning or at the end of the conditional sentence)?
There are three types of conditional sentences.
| type | |
|---|---|
| condition possible to |
|
| II | condition in theory possible to |
| III | condition not possible to |
1. Form
| type | if-clause | main |
|---|---|---|
| Simple Present | will-future or (Modal + infinitive) | |
| II | Simple Past | would + infinitive * |
| III | Past Perfect | would + have + past participle * |
2. Examples (if-clause at the beginning)
| type | if clause | main |
|---|---|---|
| If I study, | I will pass the exam. | |
| II | If I studied, | I would pass the exam. |
| III | If I had studied, | I would have passed the exam. |
3. Examples (if-clause at the end)
| type | main clause | if-clause |
|---|---|---|
| I | I will pass the exam | if I study. |
| II | I would pass the exam | if I studied. |
| III | I would have passed the exam | if I had studied. |
4. Examples (affirmative and negative sentences)
| type | Examples | ||
|---|---|---|---|
| long forms | short/contracted |
||
| + | If I study, I will pass the exam. | If I study, I'll 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 won't fail the exam. If I don't study, I'll fail the exam. |
|
| II | + | 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. |
|
| III | + | 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. |
|
* 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.
