There are three types of conditionals or if-clauses.
|
type
|
condition
|
|
I
|
condition
possible to fulfill
|
|
II
|
condition in theory possible to fulfill
|
|
III
|
condition not possible to fulfill (too late)
|
Form
|
type
|
if clause
|
main
clause
|
|
I
|
Simple Present
|
will-future (or Modal + infinitive)
|
|
II
|
Simple Past
|
would + infinitive *
|
|
III
|
Past Perfect
|
would + have + past participle *
|
Examples
(if-clause at the beginning)
|
type
|
if clause
|
main
clause
|
|
I
|
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.
|
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.
|
Examples
(affirmative and negative sentences)
|
type
|
|
Examples
|
|
|
|
|
long forms
|
short/contracted forms
|
|
I
|
+
|
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.
|
