几乎
jī hū
Expressing "nearly" with "jihu"
几乎 means "almost" — very close to the full amount, or to something happening.
Subj. + 几乎 + Verb / Adj.
How it works
他的头发几乎全白了 — his hair has gone almost completely white.
It also marks a near miss: 我几乎忘了 — I almost forgot.
差不多 is the more colloquial cousin, and it can also mean "about the same".
Examples
tā de tóu fa jī hū quán bái le
他的头发几乎全白了。
His hair has gone almost completely white.
wǒ jī hū wàng le zhè jiàn shì
我几乎忘了这件事。
I almost forgot about this.
zhè lǐ jī hū méi yǒu rén
这里几乎没有人。
There's almost nobody here.