greet sb with a nod

向某人点头打招呼

He gave me a friendly nod as he came in.

他进来时向我友好地点了点头。

I asked him if he would help me and he nodded.

我问他能否帮帮我，他点了点头。

My mother nodded (her) approval.

nodded (her) approval

She was phoning someone, so I nodded to / at her and went away.

她正在给人打电话，所以我向她点头示意后就离开了。