If David comes, he will drive you.
If David comes, = the conditional clause
he will drive you. = the main clause (result clause)
If I miss the train, I will be late for work.
If it rains today, I won’t play baseball.
If you see Tom, will you tell him to call me?
*NOTE: In spoken English, will is often contracted to ‘ll to the subject.
If I win tickets to the game, I’ll take you.
It is also possible to invert the clauses by putting the main clause before the conditional clause to add variety and also when we want to emphasise a certain part of the sentence.
So, we can also use the following structure:
*NOTE: When the main clause comes before the conditional clause, we do not use a comma before the conditional clause.
Compare the following examples with the sentences above:
David will drive you if he comes.
I will be late for work if I miss the train.
I won’t play baseball if it rains today.
Will you tell Tom to call me if you see him?
*NOTE: We can replace will/won’t in the main clause with Going to.
I will go on holiday to Polynesia next year if I have enough money.
I’m going to go on holiday to Polynesia next year if I have enough money.
We can use modal verbs in the main clause instead of will / won’t.
– use might / may / could to show uncertainty.
If it’s nice on Saturday, we might have a barbecue.
– use can / be able to to talk about ability.
If we save our money, we can go on holiday this summer.
– use should when you want to talk about something that is advisable or probable.
If they invite you to a job interview, you should wear something nice.