你对面的美女好像在跟你打招呼。

Nǐ duìmiàn de měinǚ hǎoxiàng zài gēn nǐ dǎzhāohu.

The pretty girl across from you side seems to be saying hello to you.

今天早上我有跟她打招呼。

Jīntiān zǎoshang wǒ yǒu gēn tā dǎzhāohu.

I said hello to her this morning.

我跟他打招呼的时候，他没有理我。

Wǒ gēn tā dǎzhāohu de shíhou, tā méiyǒu lǐ wǒ.

When I said hello to him, he ignored me.