Learn French: De rien, ce n'est pas un problème. - You're welcome, it is not a problem.

Literally, de rien translates to 'of nothing.' It is similar to saying 'it's nothing' or 'think nothing of it' in English when someone thanks you. It is the most common and casual way to say 'you're welcome' in everyday French.

Why is there an apostrophe in n'est pas?

To make a sentence negative in French, you put ne and pas around the verb. Here, the verb is est (is). Because est starts with a vowel, the ne drops its 'e' and attaches directly to the verb, becoming n'est. So, ce n'est pas simply means 'it is not'.

The word problème ends in an 'e'. Why does it use the masculine word un?

While many French words that end in 'e' are feminine, there are quite a few exceptions, and problème is a very common one. It is a masculine noun, so it must be paired with the masculine un (a) instead of the feminine une.