Unit 4.2

Auxiliary use of Need


A modal verb is a type of auxiliary (helping) verb that has no meaning on its own but it modifies the main verb, changes his meaning and gives more details about the action.

The verb need is both an ordinary verb and an auxiliary-modal verb.


Need, as an auxiliary-modal, always has the same form even for the third person, and we find this structure in its three forms.

When we use need as a modal verb:

  1. We do not find the to + verb after need;
  2. We form question and negative forms without the auxiliary do;
  3. We don’t apply the -ing form to need;
  4. We don’t add an -s for the third person singular;
  5. We almost always use a negative word (e.g. nobody, no one, nothing) or phrase in the clause, even if the verb phrase is affirmative.


Its structure, in the affirmative form, is:
Subject + Need + complement

I/You need work
He/She/It need work
We/You/They need work


Its structure, in the negative form, is:
Subject + Need + Not + complement

  • Negative short form is: Needn’t.
I/You need not
He/She/It need not work
We/You/They need not work


Its structure, in the interrogative form, is:
Need + subject + complement + ?

Need I/you work ?
Need he/she/it work ?
Need we/you/they work ?



  1. No one need think that physics is unnecessary.
    No one need to think that physics is unnecessary.
  2. Need we worry about the wound?
    Do we need worry about the wound?
  3. I need lose weight.
    I am needing  lose wight.
  4. She need gain weight.
    She needs gain weight.
  5. Nobody need worry about the crisis.


We use need as an auxiliary-modal verb when we refer to immediate necessity, ask for or give permission and when we make decisions about the future.


We can use need as an auxiliary and as an ordinary verb. Need expresses immediate necessity, permission and decisions about the future.

When used as an auxiliary verb, we have to remember that it accompanies the main verb, does not need to if followed by an infinitive, does not require the ending –s when we are using the third person singular and is mainly used in the negative and interrogative forms (without using the auxiliary verb do).

We can use it in its different forms:

  • Affirmative: We start with the subject followed by need and a complement.
  • Negative: We start with the subject followed by need not and a complement.
  • Interrogative: We start with need followed by the subject and a complement (the sentence ends with a question mark).

For example:
— Affirmative: “She need drink more water.”
— Negative: “She needn’t drink more water.”
— Interrogative: Need she drink more water?
♦ “She ought to drink more water.” = If we use the auxiliary ought to then we don’t talk about a necessity, but we give an advice to her to drink more water.

Let’s revise this content within the {Form} section. Take a look at the {Example} section that shows its use within a context.