1) Invert the subject and verb form and add a hyphen. Instead of Vous parlez anglais? use Parlez-vous anglais? But if you invert il, elle, or on, you must put a t between the verb form (if it ends in a vowel) and the subject for ease of pronunciation. Parle-il anglais? is incorrect and must become Parle-t-il anglais? And je is usually only inverted with pouvoir or devoir. However, if je is inverted with pouvoir, you don't use peux, but puis. Puis-je? (pweezh) is Can I?
2) Add n'est-ce pas? (ness pah) to the end of the sentence. It is equivalent to isn't it, don't you, aren't we, won't you, etc.
3) If the question requires a yes or no answer, put Est-ce que (ess kuh) at the beginning. It contracts to Est-ce qu' before a word beginning with a vowel, such as elle, il or on. You can also use interrogative words (quand, comment, où, etc.) at the beginning of the sentence and then add est-ce que.
4) With interrogative words, you can also use inversion: Quand tes parents partent-ils en vacances? Or you can use an interrogative with est-ce que and normal word order: Pourquoi est-ce que vous êtes ici?
5) Quel (which, what) agrees with the noun it modifies. It precedes the noun or the verb être, it may follow a preposition, and it can be used with inversion or with est-ce que. Quelle est la date? A quelle heure partez-vous? Quels bagages est-ce que vous prenez? Notice that the forms of quel can also be used in exclamatory sentences. Quel beau jour! What a beautiful day!
6) With negative questions, negative expressions remain in their usual place (i.e. around the verb, or verb and subject if inverted). Tu ne travailles pas? Est-ce que te ne travailles pas? Ne travailles-tu pas? Pourquoi n'as-tu pas travaillé?
Asking Questions with the Passé Composé
Only the auxiliary verb (avoir or être) and the subject pronoun are inverted. The past participle follows.
A-t-il été surpris? Was he surprised? T'es-tu amusé? Did you have fun?