explain
英 [ɪkˈspleɪn]   美 [ɪkˈspleɪn]  
v.
解释;说明;阐明;说明(…的)原因;解释(…的)理由

例句

First, I'll explain the rules of the game.

首先我要说明一下游戏规则。

I explained that an ambulance would be coming soon.

我解释说救护车很快就到。

She tried to explain but he wouldn't listen.

她试图说明一下原因，可他根本不听。