Definition of need modal verb from the Oxford Advanced American Dictionary

  

need

 modal verb
modal verb
NAmE//nid//
 
(formal)
 
jump to other results
 used to state that something is/was not necessary or that only very little is/was necessary; used to ask if something is/was necessary need (not) do something You needn't bother asking Rick—I know he's too busy. Ineed hardly tell you (= you must already know) that the work is dangerous. If she wants anything, she need only ask. All you need bring are sheets. need (not) have done something You needn't have worried (= it was not necessary for you to worry, but you did) —it all turned out fine. Grammarmodal verbsThe modal verbs are can, could, may, might, must, ought to, shall, should, will, and would. Dare, need, have to, and used to also share some of the features of modal verbs.Modal verbs have only one form. They have no past or present participles and do not add -s to the 3rd person singular form:He can speak three languages. She will try and visit tomorrow.Modal verbs are followed by the infinitive of another verb without to. The exceptions are ought to and used to:You must find a job. You ought to stop smoking. I used to smoke, but I quit two years ago.Questions are formed without do/does in the present or did in the past:Can I invite Mary? Should I have invited Mary?Negative sentences are formed with not or the short form -n’t and do not use do/does or did:You shouldn't invite Mary. The error will not have affected our results.You will find more help with how to use modal verbs at the dictionary entries for each verb. GrammarneedThere are two separate verbs need.Need as a main verb has the question form do you need?, the negative you don’t need, and the past forms needed, did you need?, and didn’t need. It has two meanings: 1. to require something or to think that something is necessary:Do you need any help? I needed to get some sleep.2. to have to or to be obliged to do something:Will we need to show our passports?Need as a modal verb has need for all forms of the present tense, need you? as the question form, and need not/needn't as the negative. The past is need have/needn’t have. It is used to say that something is or is not necessary:Need I pay the whole amount now?Need as a modal verb is used rarely and only in quite formal situations. In all ordinary situations use have to.
See the Oxford Advanced Learner's Dictionary entry: need