YOU SAID:

I think he played pretty well.

INTO JAPANESE

私は彼はかなりよくやったと思います。

BACK INTO ENGLISH

I think I've done pretty well he is.

INTO JAPANESE

私は十分良くやってます

BACK INTO ENGLISH

I've done pretty well.

INTO JAPANESE

私は十分良くやってます

BACK INTO ENGLISH

I've done pretty well.