Expressing "some" with question words

This article is a stub. Editors can help the Chinese Grammar Wiki by expanding it.

当不知道、说不出来或不便明说某事、某人、处所、时间、方式等信息时，可以用疑问代词“什么、谁”或疑问副词“在哪儿、什么时候、怎么”来虚指。

以"在哪儿"为例，句型一般是：

Obj. + Subj. + 在哪儿 + Verb + 过

More examples with different question words:

Examples

这个人我 在哪儿 见过。Zhège rén wǒ zài nǎr jiàn guo.Where did I meet this person?
这首歌我 在哪儿 听过。Zhè shǒu gē wǒ zài nǎr tīng guo.Where did I hear this song?
你让谁来帮我一下。Nǐ ràng shéi lái bāng wǒ yīxià.Who did you allow to come help me?
这件事我听谁说过。Zhè jiàn shì wǒ tīng shéi shuō guo.Who did I hear saying this stuff?
我们应该做点儿什么。Wǒmen yīnggāi zuò diǎnr shénme.What should we do?
老大，你不说点儿什么？Lǎodà, nǐ bù shuō diǎnr shénme?Boss, what did you say?
我的自行车不知道怎么坏了。Wǒ de zìxíngchē bù zhīdào zěnme huài le.I don't know how my bike broke.
他不知道怎么生气了。Tā bù zhīdào zěnme shēngqì le.He doesn't know how he got angry.
什么时候 我们见面谈吧。Shénme shíhou wǒmen jiànmiàn tán ba.What time are we meeting to talk?
什么时候 你来我新家玩吧。Shénme shíhou nǐ lái wǒ xīn jiā wán bā.What time are you coming to my new house to play?