他年纪轻轻就已经做老板了。

Tā niánjì qīngqīng jiù yǐjīng zuò lǎobǎn le.

He became a boss at a very young age.

她的年纪比我大几岁。

Tā de nián jì bǐ wǒ dà jǐ suì.

She is several years older than me.

学生们的年纪从六岁到十二岁不等。

Xué shēng men de nián jì cóng liù suì dào shí èr suì bù děng.

The students' ages range from six to twelve years old.