At this level, a person can...
Good grammatical control; occasional “slips” or non-systematic errors and minor flaws in sentence structure may still occur, but they are rare and can often be corrected in retrospect.
Shows a relatively high degree of grammatical control. Does not make mistakes which lead to misunderstanding.
Has a good command of simple language structures and some complex grammatical forms, although they tend to use complex structures rigidly with some inaccuracy.