Grammar: conditionals
Intermediate to advanced level (B1-C1)

In English there are many kinds of conditional combinations. All the sentences below are grammatically correct. 

Time: future, future
If you help me, I’m sure we can finish in about 10 minutes
If you help me, I’ll (will) buy you a drink or two in the pub tonight
If you help me, we might be able to win the competition

Time: future, future
If you gave me £10, I could buy that great T-shirt we saw in the market
If you gave me £10, I’d (would) be very grateful indeed
If you gave me £10, I might have enough to pay for the taxi

Time: past, past
If he’d (had) done it, I could have left much earlier than I did
If he’d (had) done it, I’d (would) have been really really surprised
If he’d (had) done it, he might have been arrested by the police

Can you think of any more (there are many)?

At school you might have been given some simple rules by your teacher. However, these rules are usually too simple and the real situation is a lot more complicated. Don’t be angry, your teacher was only trying to help!