Modal & Auxiliary Verbs

要 (yào) before a verb means “want to” — and often “going to”, with a sense that you've decided to act. Its gentler cousin 想 means “would like to”.

想 (xiǎng) before a verb means “would like to” — the soft, tentative cousin of 要. Use 想要 (xiǎngyào) to want a thing; and on its own, 想 also means “to miss”.

Chinese splits English “can” into three: 会 (a learned skill), 能 (ability or circumstances), and 可以 (permission). Picking the right one is the whole game.

应该 (yīnggāi) is the everyday “should / ought to”: Subject + 应该 + Verb (你应该多休息 = “you should rest more”). It never changes form, negates with 不 (不应该), and also means “should be / probably”.

Besides “or,” 还是 (háishì) has a second job: “had better,” or “it would be better to.” Once you’ve weighed the options, you announce the one you’ve chosen with (Subject +) 还是 + Verb Phrase + 吧, so 还是明天去吧 means “let’s go tomorrow after all.” The negative version is 还是 + 别/不要 + … + 了.

最好 (zuìhǎo) literally means “best,” and as an adverb it means “had better” or “it would be best to.” You use it to give advice or make a polite demand: Subj + 最好 + Predicate, as in 你最好先休息 (“you’d better rest first”). The negative is 最好 + 别/不要 + Predicate.

要不 (yàobù) is the colloquial “how about…?”, a soft suggestion that seeks the listener's agreement: 时间还早，要不再喝一杯吧 (“it's still early, how about another drink?”). It leads the suggestion, usually with 吧 or said as a question. The same 要不 also means “otherwise / or else.”

不用 (bùyòng) means “don't need to / no need to.” It's the negative of 要 (“need to”) and 得 (děi, “must”): Subject + 不用 + Verb Phrase. 孩子不用买票 (“kids don't need to buy a ticket”), 今天不用加班, 你不用担心. The trap is that “don't need to” is 不用, not 不要 (bùyào), which forbids the action (“don't!”).

得 (děi) is the auxiliary “must / have to”: Subject + 得 + Verb Phrase. 我们得走了 (“we have to go now”), 你得道歉 (“you must apologize”). It's the everyday spoken word for real obligation, lighter than the formal 必须. The catch is the character: 得 is read děi (“must,” before the verb) but also de (the complement particle, after the verb), so 你走得很快 is a totally different 得.

只好 (zhǐhǎo) is the resigned “have no choice but to / no other option but to”: a situation closes off the better paths, so you fall back on the one that's left. The frame is (cause，) (Subject +) 只好 + Verb Phrase: 电梯坏了，我们只好走楼梯 (“the lift broke, so we had to take the stairs”). It carries reluctance, which is what sets it apart from a neutral 所以 (“so”), and from 只能 (“can only,” about ability).

尽量 (jǐnliàng) is the adverb “as much as possible / to the greatest extent / do your best to.” Placement is easy: it goes straight before a verb or adjective, 尽量 + Verb/Adj, often after a modal 会 / 要 / 应该 (我会尽量早点到, “I'll get there as early as I can”). Its negative wraps the verb, 尽量不 / 尽量不要 (尽量不打扰你). Watch the attitude: 尽量 is a soft “I'll try,” not a firm promise like 一定.

尽管 (jǐnguǎn) here is the encouraging “feel free to / go ahead and”: 尽管 + Verb, right before the verb, telling someone to act without holding back. 有问题尽管问 (“feel free to ask if you have questions”), 别客气，尽管坐 (“don't be shy, take a seat”). The doer sits before 尽管, and a verb follows it. Careful: the same 尽管 before a whole clause flips to “although,” and it's not 尽量 (“as much as possible”).

不得不 (bùdébù) is the double-negative “cannot but / have no choice but to / can't help but.” Literally 不得 (“may not”) + 不 (“not”), the two negatives cancel into a strong, reluctant “have to”: circumstances have shut off every alternative and forced this one action. The frame is Subject + 不得不 + Verb: 时间不早了，我不得不走了 (“it's late, I have to go”). It's heavier and more reluctant than the flat 必须 (“must”).

千万 (qiānwàn) looks like a number (“thousand ten-thousand”) but it's an emphatic adverb for imperatives, meaning “be sure to / whatever you do / for heaven's sake.” It fronts a command and leans on a helper: 千万别 / 千万不要 / 千万不能 (whatever you do, DON'T) or 千万要 (be SURE to). It can't modify a statement of fact, so “he'll definitely come” is 一定, not 千万.

恐怕 (kǒngpà) is the apprehensive adverb “I'm afraid that / I'm concerned that / probably (unfortunately).” It marks the speaker's worried estimate about something likely but unwelcome, and softens bad news: 今天恐怕要下雨 (“I'm afraid it's going to rain today”), 恐怕我帮不了你 (“I'm afraid I can't help you”). It fronts the clause, best before the subject, and often pairs with 要 / 会 / 能 / 得. It's not the emotion verb 害怕 (“to fear”).