Des faux amis …

Grave, adj : serious, solemn.

The French word « grave » looks exactly like the English word “grave.” The problem is that the word “grave” can have a different meaning in English than it does in French.

In English, “grave” can mean “a burial place.” It can also mean “serious” or “solemn.”

In French, « grave » generally means “serious” or “solemn.”
« Grave » ! is also used in conversational French to agree with someone.

Ses blessures sont très graves.
He has serious injuries.

Ce n’est pas grave !
It doesn’t matter! / It is not serious!

Tu veux aller au cinéma ce soir ? Mais grave !
Do you want to go to the cinema tonight? Totally!