还
hái
Continuation with "hai"
还 means "still" — the situation hasn't changed yet.
Subj. + 还 + Verb Phrase / Adj.
How it works
你还在看书? — you're still reading? It marks something as ongoing past the point you'd expect it to stop.
With a negative it becomes "not yet": 我还没吃饭, 他还不知道.
还 has several other jobs — "also", "reasonably" — that share the character but not the meaning.
Examples
nǐ hái zài kàn shū?
你还在看书？
You're still reading?
wǒ hái méi chī fàn
我还没吃饭。
I haven't eaten yet.
tā hái zhù zài shàng hǎi
他还住在上海。
He still lives in Shanghai.