Very simply put, the Second Conditional is used to talk about possible, but unlikely, situations and wondering what would happen.

The little girl in the picture might think…

If I had a bike, I would go out and play with my friends.

But she doesn’t have a bike so she can’t right now.

And the little girl’s mother might think…

If Daniel Craig came and knocked on the door right now and asked me to run away with him… I might!

But let’s face it, Daniel Craig isn’t likely to do that…

As you can see, we use the second conditional to speculate, sometimes quite fancifully, about pretty impossible situations which aren’t true now (although they could be true in the future):

If I had my driving licence, I’d be able to drive legally.

In this last example although it’s an impossible situation now, in the future it might well be possible.

Forming the Second Conditional

To make the second conditional we mostly use an if clause and a main clause.

The verb in the if clause is in the simple past, whilst the verb in the main clause uses would/could/should/might:

if + {past tense} + would/could/should/might

If she went, I could get some sleep (but it doesn’t look like she’s going to leave for ages).

If they practised more they would be quite good (but they don’t want to practise more so they’re rubbish).

were

Sometimes we use the subjunctive with I, he, she, it:

If I were…
If she were…

instead of…

If I was…
If it was…

Some people think that not using the subjunctive is wrong and sounds like poor grammar. Some people think that using the subjunctive sounds wrong and is “posh”.

Useful Links

Conditionals in English Grammar – a general look at conditionals in English

First Conditional or Second Conditional – which do we use, the first or second?