帮忙翻译一下.....

He told me about that when I surfed the internet with him yesterday.
这句说的是跟他一起去上网。
假如是说跟他在网上聊，就用He told me about that when we talked on the internet yesterday.

He told me yesterday when we were chatting on the net.

I went to the internet with him yesterday,he told me about that.

Yesterday, I talked to him online, he told me that.