"You are not a student."

Translation: 你不是学生。

[shlomiabr]

Shēng sounds like shèng here.
Is it so? Can you hear it too? I know bù sounds like bú here, as it should.

[BenjaminCh29]

You are right. It is pronounced incorrectly

[DiamondGirl64]

For certain phrases or words tones can be changed or it could also be the accent/dialect of the speaker

[xaviersantana]

You can either be ni or ni men

[ace214547]

Ni men means you-all or y'all.

[jordanchfung311]

This sentence is quite easy!

You:你
are not: 不是
a student:學(学)生

[llermo6]

Has this app with speaking exercise or can you write in chinese or pinyin?