I think Diane needs have a holiday.

问题描述:

I think Diane needs have a holiday.

不对,情态动词need有时可以作实意动词,判断标准就是情态动词不可以有第三人称单数和过去式,本句中你已经用needs第三人称单数,那么就是实意动词,那么就和后面的动词have重复,那就必须把后面的动词have改成非谓语动词(可以改为needs to have或者needs having就对了);
如果前面只是need没有s那就是情态动词,那么后面就直接加动词原形.