need必须是to do形式吗？

作为情态动词时need 后直接跟动词原形,作为实义动词时有两种情况:1.主语是人时:need to do sth .主语是物时:need doing sth .所以不一定是need to do的形式．

不一定
need to do sth
和
need doing 表有需要
例如：
I need to go to pick up my brother this afternoon.

The TV set needs repairing
=The TV set needs to be repaired.

这样说：sb.needs to do sth.；sth. needs doing/to be done。

need作情态动词时后+do; 作实义动词时后+to do.