是的，我买了一部手机。

Yes, I bought a mobile phone.

我买了一部索尼手机。

I've bought a Sony mobile phone.

我把手机忘在家里了。

I've left my mobile phone at home.

我正在沙滩上，手机响了。

I was on the beach when my mobile phone rang.

我想我的手机在方桌上。

I think my mobile phone is on the square table.