French language Q&A Forum

I don't understand the use of -t- in forming a phrase.  For example, why is "she accepted" written  "accepte-t-elle" instead of "elle a accepté"?

If Halloween is feminine, shouldn’t the expression be joyeuse Halloween instead of joyeux?

Isn't the tu-form of aller "vas"?

Could you briefly tell me when to use vous avez and vous étes since both mean "you are"?

or can we use either of them is any case?

when we should use j'ai instead of je suis