need do与need to do区别 needn't do与don't need to do区别

need do 情态动词后面加动词原形 need to do 实义动词 后面加to doneed do 有必要做某事needn't do 没必要做某事need to do 需要做某事don't need to do 不需要某事need somebody do 某人有必要某事