Need means something necessary. It can be used as main, auxiliary or model verb. To need as an ordinary verb, meaning ‘require’
I need the book.
I need to go home.
I need to do it.
He needs to eat good food (in present tense if the sub. is 3rd person singular number s to be added)
They need to win the match to exist.
We need to buy food to eat tonight.
You need not do it again.
You don’t need to do it again.
She doesn’t need to come here anymore.
I don’t need to speak to her anymore.
You don’t need to meet her just now.
You need not go there to see him.
Do I need to help you?
Does he need to pass the examination again?
Do I need to finish work within two hours?
In the past tense:
I needed to know the news.
Your hair needed to dry.
He needed to clean the cloth.
We needed to meet him today.
Did you need to stand up?
Did they need to run in the race?
Did they need to attend the meeting?
Did you need to go with him?
Did you need to buy the book?
Did you need to learn the lesson?