- 得(děi, have to)
- 必须 (bìxū, must)
- 不用（bú yòng, don’t have to）
- 不必 (bú bì, not necessary)
- 应该 (yīng gāi, should)
- 不应该(bù yīng gāi, shouldn’t)
The differences between 得、必须 and 应该
得 (děi) and 必须 (bìxū) are obligation words in Chinese. 得 (děi) means “have to” and is less strong than 必须 (bìxū), which means “must.” Using 得 (děi) implies that it is necessary to do something, otherwise a goal or outcome won’t be achieved.
你发烧了，你得去看医生。(Nǐ fāshāole, nǐ děi qù kàn yīshēng.)
You had a fever, and you have to see a doctor.
我得赶快出发, 否则就迟到了。(Wǒ děi gǎnkuài chūfā, fǒuzé jiù chídàole.)
I have to set out in a hurry, otherwise I will be late.
必须 (bìxū) in Chinese is equivalent to “must” in English and expresses a high level of certainty. Failing to do something when 必须 (bìxū) is used can result in serious consequences.
你出国之前必须先办理签证手续。(Nǐ chū guó zhīqián bìxū xiān bànlǐ qiānzhèng shǒuxù.)
Before going abroad you must first obtain a visa.
Both 得 (děi, have to) and 必须 (bìxū, must) have the same meaning: expressing obligation. However, 必须 (bìxū, must) is more formal than 得 (děi, have to), which is colloquial and often used in daily life. In fact, 得 (děi, have to) is a dialect in northern China and is not used in formal writing.
The negative form of both 必须 (bìxū, must) and 得 (děi, have to) is 不用 (bú yòng), which is equivalent to “don’t have to” In English. You can also use 不必 (bú bì, not necessary), which is the same as 不用 (bú yòng).
我明天不用早起。(Wǒ míngtiān bú yòng zǎoqǐ.)
I don’t have to get up early tomorrow.
我可以自己从机场回家,你不必来接我。(Wǒ kěyǐ zìjǐ cóng jīchǎng huí jiā, nǐ bú bì lái jiē wǒ.)
You don’t need to pick me up at the airport. I can get home by myself.
The word “得” can also have the same meaning as “需要” (xūyào, need).
这辆车得多少钱?( Zhè liàng chē de duōshǎo qián? how much money needed to buy this car? )
In this sentence, you cannot use “必须” instead of “得”.
Another word that expresses necessity is “应该” (yīng gāi), which is similar to “should” in English.
我们应该帮助穷人（wǒmen yīnggāi bāngzhù qióngrén）
We should help the poor.
The negative form of “应该” is “不应该” (bù yīng gāi), meaning “shouldn’t”.
他不应该对妈妈那样说话。（Tā bù yīng gāi duì māma nàyàng shuōhuà.）
He shouldn’t talk to his mother like that.
Understanding the differences between 得 (děi), 必须 (bìxū), and 应该 (yīng gāi) will increase your fluency in Chinese by allowing you to accurately describe things that you need to do and things that you need others to do.. While these words might seem similar at first glance, each carries its own unique connotations and usage. These verbs are common in everyday life, so you will be sure to encounter them at work, at school, or when talking with friends or family. So keep practicing and incorporating these verbs into your daily Chinese conversations, and soon enough, you’ll be speaking like a native!