Modal and Auxiliary Verbs: 会, 能, 可以, 要, 想, 愿意, 应该, 得 (děi), 必须

Modal verbs are the helper verbs that sit in front of a main verb and color it: can do it, should do it, want to do it, must do it. Chinese has a tidy set of them, and they all share the same simple grammar. Here's the whole family in one place.

How modals work (the shared rules)

Before the individual words, three rules cover all of them:

They go before the main verb.

• 我能去。 — I can go.
• 你应该休息。 — You should rest.

Negate with 不 (usually), placed before the modal.

• 我不能去。 — I can't go.

Make a yes/no question by repeating the modal (A-not-A) or adding 吗.

• 你能不能来? — Can you come?
• 你会开车吗? — Can you drive?

One more: modals don't take 了, 着, or 过. They're helpers, so the aspect markers attach to the main verb, not to them.

The "can" group: 会, 能, 可以

Three words all translate as "can," but they cover different kinds of "can." (They get their own dedicated article too, so here's the short version.)

会 — can in the sense of a learned skill.

• 我会游泳。 — I can swim. (I learned how.)

能 — can in the sense of ability or possibility right now.

• 我今天不能来。 — I can't come today. (something's stopping me)
• 这里能停车吗? — Can you park here? (is it possible)

可以 — can in the sense of permission.

• 你可以走了。 — You may go now.
• 这儿可以抽烟吗? — Is smoking allowed here?

The overlap is real and these blur in practice, but the core split is skill (会), ability (能), permission (可以).

The "want" group: 要, 想, 愿意

These express desire, from soft wish to firm intention.

想 — would like to, a wish (the softest).

• 我想喝茶。 — I'd like some tea.

要 — want to, intend to (firmer, a decision).

• 我要回家。 — I want to go home.

愿意 — be willing to. This one's about willingness, agreeing to do something, not just wanting it.

• 我愿意帮你。 — I'm willing to help you.
• 他不愿意去。 — He's unwilling to go.

愿意 often shows up when there's a choice involved and you're agreeing (or refusing) to take something on.

The "should / must" group: 应该, 得, 必须

These express obligation, from gentle advice to hard necessity.

应该 — should, ought to (advice or expectation).

• 你应该早点睡。 — You should sleep earlier.
• 现在应该到了吧。 — It should have arrived by now. (expectation)

得 (děi) — have to, need to. Spoken and casual. Watch the pronunciation: here it's děi, not de.

• 我得走了。 — I've got to go.
• 你得小心。 — You have to be careful.

A quirk: 得 has no 不 form. To say "don't have to," you switch to 不用 ("no need").

• 你不用来。 — You don't have to come.

必须 — must, absolutely have to. Stronger and more formal than 得.

• 学生必须穿校服。 — Students must wear uniforms.
• 你必须告诉我。 — You must tell me.

For the negative "must not," use 不能 or 不可以 (not allowed), since 不必须 isn't used.

• 这里不能照相。 — No photos allowed here.

Quick reference

Word	Meaning	Note
会	can (skill)	learned ability; also "will"
能	can (ability/possibility)	circumstances allow it
可以	can (permission)	allowed to
想	would like to	soft wish
要	want to, intend to	firm decision
愿意	be willing to	agreeing to do it
应该	should, ought to	advice or expectation
得 (děi)	have to	casual; negative is 不用
必须	must	strong; negative is 不能

Watch the negatives

The trickiest part of modals is that several don't negate the way you'd guess:

• 得 → 不用 (not 不得)
• 必须 → 不能 / 不用 (not 不必须)
• 要 (want) → 不想 (not 不要, which means "don't!")

When in doubt, reach for 不能 or 不用 to express "don't have to" or "can't," and you'll usually be safe.

A quick recap

Modals sit before the main verb, negate with 不 in front, and don't take aspect markers. The "can" group splits into skill (会), ability (能), and permission (可以). The "want" group runs from soft (想) to firm (要) to willing (愿意). The "must" group runs from advice (应该) to casual need (得) to hard necessity (必须). Just keep an eye on those irregular negatives and the set is yours.