How do you say how are you in French?

"How are you?" is commonly, casually said 'comment ça va ?' in French.

'Ça va ?' is really informal. Use it like you are using "howdy?".

'Comment allez-vous ?' is more formal (how do you do?). There seems to be little difference, but you would use only 'comment allez-vous' when introduced to strangers or in formal meetings, and not 'comment ça va' or 'ça va' which aren't appropriate.

Different ways to reply to this are:

- 'Ça va très bien, merci' (I'm very well, thanks)-

- 'Je vais bien, et vous ?' (I'm fine, and you?)

- 'comme ci comme ça' or 'bof' (so and so)

- 'pas très bien' or 'on fait aller' (Not well / terrible, but we're not here to complain).