难道…吗？: rhetorical question
特殊句型 / special sentence patterns
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
难道 + (S) + sentence + 吗？
难道…吗？ doesn't ask for information: it's a rhetorical question expressing surprise, reproach or obviousness. The real meaning is the opposite of the form: 难道你不知道吗？ = "Surely you know!".
English: "Don't tell me…?", "Surely you don't…?". 难道 can go before or after the subject; 吗 at the end is very common.
Examples
难道你没看新闻吗？大家都知道了。
Nándào nǐ méi kàn xīnwén ma? Dàjiā dōu zhīdào le.Didn't you see the news? Everyone knows.
网上说的难道都是真的吗？
Wǎng shang shuō de nándào dōu shì zhēn de ma?Surely not everything online is true?
这么简单的道理，难道还要我解释吗？
Zhème jiǎndān de dàolǐ, nándào hái yào wǒ jiěshì ma?Such a simple point: do I really need to explain it?
Common mistakes
✗ Treating 难道…吗 as a real question: it's a reproach.
✗ 难道 + wh-question: ✗ 难道你去哪儿吗？ → 难道 goes with yes/no questions.