CONDITIONAL

Conditional sentences usually have two parts, the if clause and the then clause. The word "then" is generally omitted.

IF clause	THEN clause
If I see Mary,	(then) I will tell her to call you.
If you won the lottery,	(then) would you quit your job?
If it rains,	(then) the game will be canceled.

The if clause and the then clause can also be inverted:

Example: I will tell Mary to call you if I see her.

REAL CONDITIONAL

A real conditional expresses a realistic possibility. In the real conditional, the if clause verb is in present tense, and the then clause verb is in future tense (or a modal, or the imperative).

Real conditional examples:

IF clause (present tense)	THEN clause (future or imperative)
If I go to the store,	I will buy some milk and bread.
If he doesn't study,	he will fail the course.
If it is too cold,	We may cancel our ski trip.
If you write another poem,	please send me a copy.

IMAGINARY CONDITIONAL

An imaginary conditional expresses an unrealistic possibility. In the imaginary conditional, the if clause verb is in past tense, and the then clause verb is in conditional tense (past modal + verb).

Note: The past modals are would, could, might, should. Normally the

conditional is formed with would, although the other past modals

may be used to lend nuance. (could suggests potential ability;

might suggests a lesser probability; should is rarel used)

Imaginary conditional examples:

IF clause (past tense)	THEN clause (conditional tense)
If I had a million dollars,	I would move to a Mediterranean villa.
If he studied, (in reality he doesn't study)	he would pass the course.
If you saw a UFO,	what would you do?
If I was taller,	I could join the basketball team.

Note: In traditional English grammar, the past tense is replaced by the past subjunctive for the imaginary conditional. The only difference is that the verb TO BE = were (instead of was) for 1st and 3rd persons singular.