có ... không?

The có ... không? pattern is the most common and standard way to ask a yes-no question in Vietnamese. It translates to "Do you [verb]?" or "Are you [adjective]?". It is also perfectly standard for simple past tense questions when used with past time markers (translating to "Did you [verb]?"), whereas the đã ... chưa? pattern specifically means "Have you [verb] yet?".

How it works:

• có is placed right before the main verb or adjective. In this pattern, it is a grammatical marker, NOT the verb "to have".
• không is placed at the very end of the sentence.

Important Rules:

• Verbs and adjectives only: This pattern cannot be used with nouns. To ask "Are you a [noun]?", you must use the có phải là ... không? pattern instead.
• The "có" rule: As an excellent general rule of thumb, if the main verb of your sentence is actually có (meaning "to have"), you drop the question marker có to avoid saying "có có". For example, "Do you have time?" is Bạn có thời gian không?, not Bạn có có thời gian không?. However, native speakers occasionally use "có có" to add strong emphasis or skepticism (e.g., Bạn có có tiền không? - Do you actually have money?).
• Using with tense markers: The có marker can wrap around the continuous marker đang. The structure becomes Subject + có + đang + Verb + không? (e.g., Bạn có đang làm việc không? - Are you working?). For future yes-no questions, native speakers typically drop có (e.g., Bạn sẽ đi không? - Will you go?) or simply use có ... không? with a future time word (e.g., Ngày mai bạn có đi không? - Are you going tomorrow?). However, using có sẽ ... không? (e.g., Bạn có sẽ đi không?) is still a grammatically valid and accepted structure in formal contexts. For past actions, combining có and đã (e.g., có đã ... không?) is unnatural. Instead, simply use có ... không? with a past time word, or use the đã ... chưa? pattern to ask if something has happened yet.
• Dropping the marker: In casual, everyday spoken Vietnamese, native speakers frequently drop the có marker entirely. You will often hear Bạn khỏe không? instead of Bạn có khỏe không? (Are you well?).
• Pronouns: Vietnamese is a highly pro-drop language. While dropping subject pronouns can sound blunt or rude when speaking to elders or superiors, dropping the subject is perfectly natural, common, and efficient in casual contexts among friends, peers, and family.
• Politeness: To show respect to elders or superiors, append the polite particle ạ to the very end of the question (e.g., Anh có mệt không ạ?).
• Intonation: Because the word không has a flat tone, your voice should not pitch up at the end of the sentence like it does in English yes-no questions. While the overall sentence melody might be slightly elevated for a question, the relative tone of the word không must remain flat.
• How to answer: You can simply answer with Có (Yes) or Không (No). Alternatively, you can echo the main verb or adjective. If someone asks Anh có mệt không? (Are you tired?), you can answer Có or Mệt (Yes), and Không or Không mệt (No). If the question asks if you have something (where the main verb is có), the negative answer can be không có (I don't have) or simply Không. Additionally, native speakers frequently answer with Chưa (Not yet) if the action might still happen, as a flat Không can sound too blunt or final.

Note that this pattern can be used for past, present, or future actions and states of being. However, if you specifically want to ask if someone has done something yet, you should use the ... chưa? pattern instead.