What is the equivalent use of need and need + Verb?

Question

If I see someone struggling to pick up a box, I'd say: "Do you need help with that?"

Or I have to run an errand very soon, I could say: "I need to buy this gift by 4 pm."

Or if someone's car has stopped working, I could say: "Do you need a lift?"

Do the Japanese use the word "need" in this way? Or is there a special word/particle/ending that provides the same usage/function?

Answer 1

You could say (noun)が必要【ひつよう】だ or (verb plain form)必要がある.

その仕事には{協力/協調}が必要だ　→　That work requires cooperation.
彼に話す必要がありますか　→　Is it necessary to tell him?

However, this would probably sound patronizing if you were asking someone like "Do you need help with that?" Might just be better to ask if you can help them do the thing.

それを手伝いましょうか　→　Shall I help you with that?

"Need" can also be interchangeable with "must" depending on the context, so you can use the {なければ／なきゃ／なくては／ないと}＋{ならない／いけない／だめ} form.

4時までにプレゼントを買う必要ある　→　I need to buy a gift by 4:00
4時までにプレゼントを買わないといけない　→　I must buy a gift by 4:00 (lit., "It won't go over if I don't buy a gift by 4:00")