How To Use Need In English

The verb need may be either a modal or a regular verb

• Need as a regular verb has tense forms, it is followed by the to-infinitive. It forms its negative and interrogative forms with the auxiliary verb to do.
  • Do I need to show my pass every time?
  • You don’t need to say it every time you see me
  • You didn’t need to tell me about it
• Need is close to to have
  • Did you need to read all these books? = Did you have to read all these books?
• Need as a modal verb is used in negative and interroga­tive sentences only. It expresses necessity. As a modal verb it has no past tense form; it is used without -s in the third person singular
  • You needn’t do it now
  • Need she come tomorrow?
• In negative sentences need followed by the Perfect Infini­tive shows that the unnecessary action was performed
  • You needn’t have spent all the money. Now we’ve got nothing left.
• Need not can be contracted to needn’t. We don’t use don’t/doesn’t/didn’t with the semi-modal verb need
  • She needn’t apologize