Affirmative-negative questions: V 不 V / V 没 V
【一33】【一48】正反问句
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
Subject + V 不 V (+ Object)？ / Subject + V 没 V？ / … 了没有？
Another way to ask a yes/no question: say the verb (or adjective) in positive then negative form: 你去不去？ (are you going or not?). 这本书贵不贵？ (is this book expensive?).
The middle 不 is toneless: qù bu qù.
With two-syllable words you can split: 好看不好看 or 好不好看.
For a past action, use 没: 他去没去图书馆？ or 他去图书馆了没有？ (did he go to the library?).
This form is already a question, so no 吗!
Examples
你吃不吃包子？
Nǐ chī bu chī bāozi?Do you eat steamed buns or not?
这本书贵不贵？
Zhè běn shū guì bu guì?Is this book expensive?
电影好看不好看？
Diànyǐng hǎokàn bu hǎokàn?Was the movie good?
你是不是老师？
Nǐ shì bu shì lǎoshī?Are you a teacher or not?
他回家了没有？
Tā huí jiā le méiyǒu?Has he gone home?
Common mistakes
✗ 你去不去吗？ → ✓ 你去不去？
✗ 这个很贵不贵？ → ✓ 这个贵不贵？ (no 很).
✗ 你有不有？ → ✓ 你有没有？