IELTS

Idioms can be used to show your range in the language.

I used to tell students not to worry about them because there are so so many and they are so difficult to learn how to use properly. You might hear an idiom and recognize its meaning, but when you come to using it in your own speech or writing, you'll probably run into difficulty.

But if you want a high score, you should definitely learn a few high-frequency idioms that can be used in a variety of situations. Let's look at an example:

a hope in hell

It's a useful idiom, which can be used in any situation where you had no chance at all. Learn it in context, as a language chunk. Google "hope in hell" to get some ideas. And then think of all the situations you can use it in.

I studied hard, but I didn't have a hope in hell of passing -- it was just too difficult.

I love Japan, but there's not a hope in hell that I'll ever be able to live there.

I once tried sculpture, but I'm not artistic -- I didn't have a hope in hell of creating even a nice pot.

By using a a few choice idioms, you'll be tricking the examiner into thinking that you have a wide range in English. You might only know how to use a few, but at least you'll know them well and be able to use them with confidence.