need作为行为动词可用于三种结构:1) 主语+ need + n. I need a good job.
2) 主语+ need to + v. We need to buy some food.
3) 主语+ need+ ving.= The desk needs mending=
主语+ need to be done. The desk needs to be mended.
need有人称和数的变化,否定和疑问要借助助动词。
need作为情态动词多用于否定句和疑问句: Need I finish it now?
Yes,you need.\No,you needn't( finish it now) .
注意: 以上规律,need可以用于各个人称,只是用于第一人称疑问句时 ,回答有些例外。望对您有所帮助。
参考资料:中学生英语语法