1 如果need后面接的是动词原型need do ,need就是情态动词:He needed buy a bike.
2 如果need后面接的是need to do(表示主动)和need doing(表示被动),need就是实意动词
He needs to sleep.
The task needs washing.
3 如果need后面接的是名词,need就是实意动词
He needs a car.