have been to 去哪现在已经回来
have gone to 去哪现在还没回来.
都用在现在完成时态当中.
例如： I have been to Dalian four times
我去大连四次了（说明现在已回来）
He has gone to Dalian , he will be back in two days.
他已经去大连了,两天后回来.（去还没有回来）