There are 20 of us vs. We are 20

WRONG: We are 20.
RIGHT: There are 20 of us.

A very common mistake concerns how we count the number of people somewhere. In Czech, it is normal to say a phrase like, „We are 20“, meaning there are 20 people. But if you say this in English, it makes the listener think you are referring to their age. They think you are saying, „We are 20 years old.“

Instead, English people say the rather more difficult construction of „There are 20 of us.“ You can say, „There are 20 people“ but with this phrase, it is not immediately clear if that number includes you. Saying, „There are 20 of us“ makes sure that the listener knows you are included in the total number.

Look at this dialogue between a man and a waiter to see the difference:

Man: Can my friends and I have a table?

Waiter: How many of you are there?

Man: There are 6 of us.

Waiter: OK, sure, there are only around 10 people in the restaurant at the moment. Sit where you like.