- ZERO CONDITIONAL
If - clause: Present Simple
Main-clause: Present Simple
Use: a general truth or situation
e.g. If you heat water, it boils.
- FIRST CONDITIONAL
If - clause: Present Simple
Main-clause: will + bare infinitive / can, may, might, should, ought to + verb / imperative
Use: sth possible to happen in the future
e.g. If I tell you the secret, Anna will/may be furious.
If you see John, tell him to call me.
- SECOND CONDITIONAL
If - clause: Past Simple
Main-clause: would, could, might, should, ought to + bare infinitive
Use: sth what is unlikely to happen in the future or a hypothetical situation
e.g. If I were rich, I would buy a villa in Dubai.
- THIRD CONDITIONAL
If - clause: Past Perfect (had + p.p.)
Main-clause: would (or modal) + have + p.p.
Use: sth that could have happend differently in the past
e.g. If you had brought a map, we wouldn't have been lost.
- MIXED CONDITIONAL
If - clause: Third conditional (If + Past perfect)
Main-clause: Second conditional (would + verb)
Use: the result of a past action to the present
e.g. If you had eaten that sandwich, you wouldn't be hungry now.