How do you say very interesting in French language?

There are a few ways to say "very interesting" in French, depending on the context and desired level of formality:

Formal:

* Très intéressant: This is the most common and literal translation, meaning "very interesting."

* Extrêmement intéressant: This is more emphatic, meaning "extremely interesting."

Informal:

* C'est super intéressant: This is a more casual way to say "that's super interesting."

* C'est vraiment intéressant: This is a slightly more formal way to say "it's really interesting."

* C'est vachement intéressant: This is a very informal expression, similar to "that's awesomely interesting."

Other options:

* Fascinant: This means "fascinating" and is a more intense way to express interest.

* Captivant: This means "captivating" and suggests something that is deeply engaging.

The best way to choose the right expression depends on your audience and the context of the conversation.