Advanced uses of "hai"

Aside from its other uses, 还 (hái) can be used to express a surprised or sarcastic tone, and can also be used with rhetorical questions.

Expressing a Tone of Surprise

Often used with 呢, this sentence structure expresses that the situation as irrational, uncommon, or unexpected.

Subj. + 还 + Predicate (+ 呢)

这个小孩还真聪明！Zhège xiǎohái hái zhēn cōngming!This kid is brilliant!
还留过学呢，英语这么差！Hái liú guo xué ne, Yīngyǔ zhème chà!He's even studied abroad, yet his English is so terrible!
都怪你，你还生气呢。Dōu guài nǐ, nǐ hái shēngqì ne.It's all your fault, yet you're the one who's mad.

It can also be used to express astonishment, dissatisfaction, or sarcasm.

Subj. + 还 + Noun Phrase (+ 呢)

还好朋友呢，天天说我坏话。Hái hǎo péngyou ne, tiāntiān shuō wǒ huàihuà.What a "good friend"! Talking trash about me every day.
还大老板呢，一点也不大方。Hái dà lǎobǎn ne, yīdiǎn yě bù dàfang.Some "big boss," not generous in the least.
还夸我中文好呢，我说的每句中文你都纠正我。Hái kuā wǒ zhōngwén hǎo ne, wǒ shuō de měi jù zhōngwén nǐ dōu jiūzhèng wǒ..You also complimented me on my good Chinese, and you corrected me on every Chinese sentence I said.

还 can change a statement into a rhetorical question when used with 吗.

Subj. + 还 + [Verb Phrase] + 吗 ?

他那么有钱，还在乎这点钱吗？Tā nàme yǒu qián, hái zàihu zhè diǎn qián ma?He has so much money, would he really care about this small amount?
这种人你还相信吗？Zhè zhǒng rén nǐ hái xiāngxìn ma?Would you believe this kind of person?
过期的牛奶你还喝吗？Guòqī de niúnǎi nǐ hái hē ma?Would you drink expired milk?
今天这么热，你还出门吗？Jīntiān zhème rè, nǐ hái chūmén ma?It's so hot today, yet you're going out now?
他说的话，你还听吗？Tā shuō de huà, nǐ hái tīng ma?Are you going to listen to what he says?