expressing obligations
50.1应当/應當 yīngdāng is more formal than 应该/應該 yīnggāi and can be used in formal texts
including legal documents. 该/該 gāi is used in informal speech. 应/應 yīng is used in formal
texts including legal documents.应该/應該 yīnggāi
父母应该照顾他们的孩子。
父母應該照顧他們的孩子。
Fùmǔ yīnggāi zhàogù tāmen de háizi.
Parents should take care of their children.应当/應當 yīngdāng
你有错误就应当改正。
你有錯誤就應當改正。
Nǐ yǒu cuòwù jiù yīngdāng gǎizhèng.
When you make a mistake, you should correct it.该/該 gāi
我该去上班了。
我該去上班了。
Wǒ gāi qù shàngbān le.
I should go to work.In legal documents, 应/應 yīng often means ‘shall.’
经济合同被确认无效后，当事人依据该合同所取得的财产，应返还给对方。
經濟合同被確認無效後，當事人依據該合同所取得的財產，應返還給對方。
Jīngjì hétóng bèi quèrèn wúxiào hòu, dāngshìrén yījù gāi hétong suǒ qǔ dé de
cáichǎn, yīng fǎnhuán gěi duìfāng.
After an economic contract has been confirmed to be invalid, the parties shall return to
each other any property that they have acquired pursuant to the contract.应/應 yīng may occur in legal texts to specify moral, though non-legal obligations. The follow-
ing is an excerpt from Section 1, Article 3, of the Child Welfare Law of Taiwan.
父母、养父母或监护人对其儿童应负保育之责任。
父母、養父母或監護人對其兒童應負保育之責任。
Fùmǔ, yǎng fùmǔ huò jiānhù rén duì qí értóng yīng fù bǎoyù zhī zérèn.
Parents, foster parents, or legal guardians should bear the responsibility of rearing the
children in the household.C12.4.250.1.3 expressing negative obligations: need not, do not have to
The Mandarin words used to indicate that an action need not be done are 不必 bù bì, 不用
bù yòng, 甭 béng, 不须/不須 bù xū, and 无须/無須 wú xū.
不必 bù bì他们明天不必来上课。
他們明天不必來上課。
Tāmen míngtiān bù bì lái shàng kè.
They don’t have to come to class tomorrow.
不用 bù yòng你不用谢我。谢她。
你不用謝我。謝她。
Nǐ bù yòng xiè wǒ. Xiè tā.
You don’t have to thank me. Thank her.