一⋯⋯也 / 都不
yī …… yě / dōu bù
Expressing "not even one"
一 plus a measure word plus 也/都 plus a negative is the emphatic "not a single one".
一 + Measure Word (+ Noun) + 也 / 都 + 不 / 没 + Verb
How it works
一句中文都不会说 — can't speak a single word of Chinese.
The 也 or 都 is compulsory; without it the sentence falls apart.
Use 不 for habitual or general statements and 没 for things that didn't happen: 我一个人也没看见.
Examples
tā yí jù zhōng wén dōu bú huì shuō
他一句中文都不会说。
He can't speak a word of Chinese.
wǒ yí gè rén yě méi kàn jiàn
我一个人也没看见。
I didn't see a single person.
wǒ yì fēn qián dōu méi yǒu
我一分钱都没有。
I haven't got a penny.