还X呢: and you call that X? (sarcasm)
【四73】口语格式 / fixed patterns
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
还 + noun + 呢 is a sarcastic formula: you pick up someone's label (or your own) and at once show that it doesn't fit. 还大学生呢，人还没出门就想哭了？: “and you call yourself a university student? You want to cry before you've even left home!”
The noun is a status, a role or a quality (大学生, 老师, 专家, 朋友, 名牌), and the rest of the sentence supplies the proof to the contrary. It is spoken, it opens the sentence (or follows the proof: 连这个都不知道，还专家呢!) and it is always critical, never a compliment. No 是 between 还 and the noun.
Watch the false friend: 还……呢 also exists without sarcasm, with 还 meaning “still”: 时间还早呢 (“it's still early”), 他还在睡觉呢. There 还 comes before an adjective or a verb, not a status noun. Nor is it the admiring 还 of 的确 and 还 (他还真有办法).
Examples
还朋友呢，我病了你也不来看我！
Hái péngyou ne, wǒ bìng le nǐ yě bù lái kàn wǒ!Call yourself a friend? I'm ill and you don't even come to see me!
还大学生呢，连这个都不知道！
Hái dàxuéshēng ne, lián zhège dōu bù zhīdào!And you call yourself a university student? You don't even know this!
还名牌呢，我听都没听过。
Hái míngpái ne, wǒ tīng dōu méi tīng guo.A famous brand? I've never even heard of it.
还专家呢，这点小事都说不清楚。
Hái zhuānjiā ne, zhè diǎn xiǎo shì dōu shuō bu qīngchu.Some expert! He can't even explain a small matter like this.
连这个都不知道，还老师呢！
Lián zhège dōu bù zhīdào, hái lǎoshī ne!He doesn't even know this, and he calls himself a teacher!
时间还早呢，不用着急。
Shíjiān hái zǎo ne, búyòng zháojí.It's still early, no need to hurry (here 还 just means “still”, with no sarcasm).
Common mistakes
✗ 他是有名的专家呢，这点小事都不会。 → ✓ 还有名的专家呢，这点小事都不会！ (the noun follows 还 directly, with no 是).
✗ 还好朋友呢，谢谢你！ → ✓ 你真是我的好朋友，谢谢你！ (还X呢 is always critical, never a compliment).