We can use main verb need as an alternative to semi-modal need. Main verb need is followed by to and it changes with person, number and tense (I, you, we, they need to; she, he, it needs to; I, you, she, he, it, we, they needed to). …

When used as a main verb, need agrees with its subject, takes to before the verb following it, and combines with do in questions, negations, and certain other constructions: He needs to go. Does he need to go so soon? He doesn't need to go.

need (third-person singular simple present needs, present participle needing, simple past and past participle needed) Living things need water to survive. You do not always need to go to the library to study. You may use the Internet.

NEED definition: a requirement, necessary duty, or obligation. See examples of need used in a sentence.

If you need something, or need to do something, you cannot successfully achieve what you want or live properly without it. He desperately needed money. I need to make a phone call. I need you to do something for me.

Need, necessity imply a want, a lack, or a demand, which must be filled.

Needs are distinguished from wants. In the case of a need, a deficiency causes a clear adverse outcome: a dysfunction or death. In other words, a need is something required for a safe, stable and healthy life (e.g. air, water, food, land, shelter) while a want is a desire, wish or aspiration.