used to correct what you have just said or to add more information

I really do love him - as a friend, I mean. 我真的爱他——我的意思是，作为朋友。

something that people often say before they start or continue their sentence

I mean, he's a good teacher, but I just don't like him. 我是说，我觉得他是个好老师，只是我不喜欢他。