We use conditional sentences to say one thing depends on another. They can be used to talk about real or imaginary situations. One of the clauses starts with if (or a similar word) – this is the conditional clause. The other clause talks about the result of the conditional clause happening.
Don’t worry, it’s a lot easier than it sounds. Let’s look at some examples.
If you don’t tell me, I’ll just keep asking.
If I promise to travel less, will you forgive me?
I know that one. It’s a first conditional: if + present simple, then will + infinitive.
That’s right. It’s for talking about a situation in the future which the speaker thinks is quite possible. If the first condition happens, something will happen as a result. In this conditional sentence, the present tense after if refers to the future, not the present.
And can you change the order of the clauses round?
Yes, and we leave out the comma in the middle of the sentence if the order is changed round.
I’ll just keep asking if you don’t tell me.
OK. I also know the second conditional. If + past simple, then would + infinitive.
Right again! This is for talking about an unlikely or unreal condition.
If you travelled less because of me, I’d feel worse.
If I had the opportunity to visit places like that, I wouldn’t complain!
So, in the second example, Oliver doesn’t think he will have the opportunity to travel a lot. It’s possible but improbable. We use the past simple to show that it’s not likely, not to indicate past time.
Can you use any other verbs, apart from would, in this kind of conditional?
Yes, we sometimes use other modal verbs like might or could in the result clause (not the if clause).
I see. What about, 'If you mix blue and yellow, you get green'. Is that a conditional?
Yes. That’s a zero conditional. We often use them for facts, or in academic subjects.
When it rains a lot, the animals move to higher ground. (geography)
What about other words that can replace if, like unless and as long as?
Well, unless is a kind of negative version of if.
I’ll never go unless you take me. (= If you don’t take me, I’ll never go.)
As long as imposes a condition on someone. You’re telling them what you expect them to do.
You can borrow my surfboard as long as you get it back to me by five o’clock.
So if you agree to what I say, you can borrow my surfboard?
Are there any other conditionals?
Well, there’s the third conditional, but we’ll deal with that separately.
Phew! Now, if you don’t mind, I’ll have to stop there.
That’s fine, as long as everything’s clear!