Closed ("yes-no") Question Forms
The easiest, most informal, and most common way to form a closed ("yes-no") question in French is simply to add a question mark and raise the tone of voice at the end of a simple statement. "Tu as un livre?" = "Do you have a book?"
Otherwise, you can always add the fomula "Est-ce que" in front of the statement: "Est-ce que tu as un livre?"
It is very formal, therefore rare, but correct, to invert the verb and subject; "As-tu un livre?". When doing this inversion, be careful of the verb "pouvoir" (can, may) with "je", which changes spelling and pronunciation "Puis-je vous aider?" (Can I help you?), but NEVER "Peux-je vous aider?".
Okay, your question is justified. I try to explain it. Pouvoir is one of the most common French verbs. It is irregular in conjugation and literally means "can" or "to be able to." Pouvoir has different meanings in certain tenses and is found in numerous expressions.
The Conjugations (Present tense)
je peux, puis
Puis is an alternative to peux, the most common first person singular conjugation. Puis is usually used for questions:
Puis-je vous poser une question ? May I ask you a question?
Puis-je vous aider ? May I help you?
When you have other question, write me. Or check out: DeNani French lessons. ♥
Does the same also hold for the first person singular conjugation of the verb vouloir? And any other verbs that are conjugated similarly to pouvoir?