Translation

• (before a noun) Do (you, they etc) have ...?
• Is there a ...?
• (before a verb) Did (you, they etc) (verb, infinitive)?
• Have (you, they etc) (verb, past participle)?

Examples

• 你有没有缝纫针？
  Do you have a sewing needle?
• 你有没有发现他说话的语气有点古怪？
  Did you pick up on that strange tone in his voice?
• 你们有没有纸？
  Do you have paper?
• 请问有没有双人房？
  Do you have a double room?
• 这城里有没有博物馆？
  Is there a museum in this town?
• 请问这儿附近有没有厕所？
  Excuse me, is there a toilet nearby?