optional

/ˈɒpʃənl/ (bre, ipa) · /ˈɑːpʃənl/ (ame, ipa) · /ˈäp-sh(ə-)nəl/ (ame, mw)

optional — 形容詞

1. available only if someone decides to include it or do it, rather than because a

1.形容詞B2
釋義

可選的

可自行決定是否加入或進行

available only if someone decides to include it or do it, rather than because a rule says it is needed

例句

Students can join the museum trip, but the visit is optional.

學生可以參加博物館那趟校外教學，但那個行程是可選的。

pattern: be optional

The hotel charged extra for optional breakfast on the second day.

旅館第二天的早餐是可選的，要另外收費。

collocation: optional breakfast

同義詞
  • voluntary

    often used when a person freely chooses to do something

  • elective

    used especially for school subjects or some medical treatment choices

  • extra

    more informal and often used for added features or services

反義詞
  • compulsory

    states that a rule requires it

  • mandatory

    more formal and common in rules, law, and official instructions

  • required

    the broad everyday opposite

文法句型

be optional

optional extra

optional course

用法筆記

Often used after be and commonly applied to classes, fees, extras, trips, and parts of a form. Distinguish from possible, which is about what may happen, not about a person's choice.

常見錯誤

❌Rain tomorrow is optional.
✅Going tomorrow is optional.
💡optional describes a choice someone can make, not an event that may or may not happen.