1. Explain it simply
Question word + 都 covers all cases: 什么都 = everything, 谁都 = everyone.
Say the question word first, then 都, then the verb.
With 不 or 没 it becomes 'none': 谁都不认识他 = no one knows him.
Keep 都 right after the question word; don't drop or move it.
2. Show examples
他什么都知道。
Tā shénme dōu zhīdào.
He knows everything.
everything
谁都不认识他。
Shéi dōu bù rènshi tā.
Sandhi:Shéi dōu bú rènshi tā.
No one knows him.
no one
我什么都想吃。
Wǒ shénme dōu xiǎng chī.
I want to eat anything.
anything
我哪儿都不想去。
Wǒ nǎr dōu bù xiǎng qù.
I don't want to go anywhere.
nowhere
3. Share a tip
都 must stay right after the question word - moving it breaks the 'any / every' meaning.

