老师，我以前见过他。

Lǎoshī, wǒ yǐqián jiànguo tā.

Teacher, I have seen him before.

我小时候见过雪。

Wǒ xiǎoshíhou jiànguò xuě.

I saw snow when I was a child.

我见过他一次，但是不太熟。

Wǒ jiànguo tā yí cì, dànshì bú tài shú.

I have met him once, but I don’t know him well.