Not… but rather… (不是…而是…)

Structure 不是 + A，而是 + B

不是…而是… (bùshì… érshì…) corrects: it denies A and puts B in its place. 这不是茶，而是咖啡 = "this isn’t tea, but coffee". It clarifies what something really is against a wrong assumption. Don’t confuse it with 不是…就是… ("either one or the other").

Examples

这zhè不bù是shì茶chá，而ér是shì咖kā啡fēi。
This isn’t tea, but coffee.
我wǒ不bù是shì不bù想xiǎng去qù，而ér是shì没méi有yǒu时shí间jiān。
It’s not that I don’t want to go, I just have no time.
他tā不bù是shì老lǎo师shī，而ér是shì学xué生shēng。
He isn’t a teacher, but a student.

Levels are indicative: they follow the standard Chinese Grammar Wiki (AllSet Learning) progression, not an official HSK 3.0 mapping. We never assign levels by eye.

This point and the other 370, with audio on every example, inside Wanyu.