You can improve your English this year.

It's definitely on the cards.

Huh!? On the cards!?

What does that mean? We don't have any cards.

'On the cards' is an idiom which means something that is likely to happen.

So if I say to you, 'Improving your English is on the cards', do I think that it's likely that it will happen or not likely it'll happen?

I think it's likely that it will happen.

Another example could be 'It's on the cards for them to get married this year.'

So do I think they are going to get married this year?

Yes.

Do I think it's likely for them to get married?

Yes.

So try this idiom with your friends, and if they don't know the meaning, you can teach them.