Conditionals

We use the second conditional to talk about hypothetical or imaginary situations in the present or the future. We can use past simple or past continuous in the if-clause and we can use would, could or might + simple infinitive (do) or continuous infinitive (be doing) in the main clause.

If there was a fire, it would be impossible to escape.
If you weren’t making so much noise, I could concentrate.
I wouldn’t have a car if I lived in the city.
If it weren’t for him, I might not be talking to you right now.

When we use the verb be in the if-clause, we can use either was (more formal) or were (spoken English) after I, he, she or it. But when we are giving advice, we always use if I were you (NOT was).

If he was/were rich, he wouldn’t be living in this house.
If I were you, I’d call him as soon as possible. (NOT was)

As with all conditional types, we use a comma after the if-clause when it goes at the beginning of the sentence, but we don’t use a comma when the if-clause goes at the end.

If you weren’t making so much noise, I could concentrate.
I could concentrate if you weren’t making so much noise.

We use the third conditional to talk about hypothetical or imaginary situations in the past. We can use the past perfect simple or past perfect continuous in the if-clause and we can use would, could or might + the perfect infinitive in the main clause.

If you had come to class more often, you would have passed the test.
I wouldn’t have been late if I hadn’t overslept.
He could have died if he hadn’t been wearing a helmet.
If the jacket had been a bit cheaper, I might have bought it.

We use the zero conditional to talk about general truths or results that always happen if a condition is present. We are talking in general, not about one particular situation.

If milk smells bad, I don’t drink it.
If water reaches 100 degrees, it boils.
If I’ve drunk, I never drive.
If people are talking all the time, I can’t concentrate.

We can put the main clause at the beginning. Then we don’t use a comma between the two clauses.

I never go to bed late if I have to get up early.

We can usually replace the if in this conditional with when without changing the meaning.

Dogs can attack you when you are scared.
When the weather is bad, people don’t go shopping.

First vs zero conditional
We use the first conditional to talk about a particular situation, whereas we use the zero conditional to talk about what happens in general.

If you don’t use oil, it tastes awful. (I’m talking about what happens every time.)
If you don’t use oil, it will taste awful. (I’m talking about this particular occasion.)

The first conditional is used to talk about things that might happen in the future if a condition is present. We don’t know if those things will happen or not, but they are a real possibility.

If you study, you’ll pass.
If he doesn’t call you, tell me immediately.
If you’ve come to class, the exam is going to be easy.
If you help me, I’ll have finished by the end of the month.

We don’t use will in the if clause.

I’ll help you if you need me (NOT if you will need me)

Unless = if (not)
We can also use unless in conditional sentences to mean if … (not)

I won’t go on holiday unless I save some money. =
= I won’t go on holiday if I don’t save some money.

Second and third conditionals

In a second conditional we use past in the if clause and would/might/could + infinitive in the main clause. It is used to talk about hypothetical situations happening in the present or future.

If I were rich, I‘d buy that house.
In a third conditional we use past perfect in the if clause and would/might/could + have + past participle in the main clause. It is used to talk about hypothetical situations happening in the past.

If you had studied more, you would have passed the exam.
A mixed conditional is a combination of second and third conditionals.

Mixed third/second conditional

We use this combination to talk about a hypothetical condition happening in the past (third conditional) with a present result (second conditional). We use past perfect in the if clause and would/could/might + infinitive in the main clause.

If I had been elected, I would be the president now.
If I had won the lottery, I would be rich.
I might have a better job now if I hadn’t dropped out of school.

Mixed second/third conditional

We use this combination to talk about a hypothetical condition happening in the present (second conditional) with a past result (third conditional). We use past in the if clause and would/could/might + have + past participle in the main clause.

If I were a man, they would have given me the job.
If I didn’t have so much work, I would have gone to the party last night.
I would have understood them if I spoke German.
Note that in this type of combination, the present condition also existed in the past, when the result in the main clause took place. Let’s take a look, for example, at the first sentence:

If I were a man, they would have given me the job.
If I were a man now would mean that I would also have been a man in the past, when I was not given the job. As I’m not a man now (which implies that I wasn’t a man when I applied for the job either), I didn’t get the job.