Conditional sentences

a. Zero Conditional

Things which are true.       IF+ Present simple, present simple

E.g. If Sam phones, tell him to meet me at the library.

b. First Conditional

Things that are possible in the future          IF+ Present simple, future

Example. If I pass the exam, I will go to Paris.

c. Second Conditional

Used when the speaker is thinking in a situation that will probably not happen.       IF Past simple, would+infinitive

E.g. If I were rich, I would move to London.

d. Third Conditional

It's used to talk about actions that have no remedy      IF Past perfect+would have, +past participle