B1 · Intermediate

Need To: The Practical Must

Need to says the job is necessary; needn’t says it is not. One word, two faces: a normal verb (need to) and a modal (needn’t).

01

Need To

Necessity, without the drama

Must and have to carry feelings and rules. Need to is the practical one: the task simply demands it. And when the task does not, you have two ways to say it — don’t need to and needn’t.

🎯

Need to — necessary

the task demands it

I need to buy milk

👤

Needs to — he/she/it

a normal verb takes -s

She needs to sleep more

🌤️

Don't need to — no need

optional, your choice

You don't need to book a table

🪶

Needn't — the modal twin

same idea, modal manners

You needn't worry about it

⚠️ Don't need to = no need. Needn't = the same idea in modal clothes — no -s, no to after it.

02

The Formula

Two grammars in one word

Need to is a normal verb: it takes -s, builds negatives with don’t and questions with do. Needn’t is a modal: it stays bare and takes a bare verb.

⚙️3つの形すべてで同じ構造
Positive
Ineed tobuysome milk

Ineed to buysome milk

Positive — he/she/it
Sheneeds tosleepmore

Sheneeds to sleepmore

Negative — normal verb
Youdon't need topay

Youdon't need to payanything

Negative — modal
Youneedn'tcome

You needn't comeif you're busy

Question
DoIneed tobook?

Do Ineed to booka table?

03

Common Mistakes

Four need traps

The traps come from forgetting which face of need you are using: the normal verb wants its to, the modal refuses it.

I need go to the bank.

I need to go to the bank.

💡 As a normal verb, need takes to + bare verb.

She need to study harder.

She needs to study harder.

💡 Normal verb rules: she needs to.

You needn't to come.

You needn't come.

💡 After needn't the verb is bare — no to.

Do I need to to pay?

Do I need to pay?

💡 One to is enough: do + need to + verb.

04

Quick Quiz

Test what you just learned

Three minutes, five questions — check what stuck. No essay questions, we promise.

問題 1 / 50 / 5

I ___ buy some stamps.

💡 追加情報2 セクション
05

Necessity or Not?

One question, two doors

Every obligation sentence starts with the same question. Your answer picks the word.

Is the action required — or is it optional?
Required — need to / have toWe need to leave now, it is late
Optional — needn’t / don’t have toYou needn't call — I will text you
06

The Obligation Family

Four words, four degrees

Need to shares the neighbourhood with three cousins. Match each one with its meaning.

need to
necessary (practical)the task demands it
don't have to
not necessaryoptional
needn't
not necessary (modal)bare verb after it
mustn't
forbiddendo not do it

⚠️ The two negatives are different again: needn’t leaves the door open, mustn’t locks it.

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