用英语表扬一个人很负责任怎么说

be responsible;conscientious
如:
这一片的矿警很负责任！
The mining police in this area are responsible

据我所知，他是一个很负责任的人。
He is a quite conscientious man so far as I know.

you are very reliable!

英汉文化有很大的差异，一个人很负责任在英语文化力只是他做好了自己该做的工作，是起码的应该做的分内的事情，所以译成reliable比较贴切。但是在汉语里面负责任所表达的意思就广博的多。

You are a responsible man.

You have done a good job. Excellent!