rat on

IPA/ɹˈat ˈɒn/
IPA/ɹˈæt ˈɔn/

rat on — phrasal verb

  • rat onbase form
  • rats on3rd person singular
  • ratting on-ing form
  • ratted onpast simple

1. to tell someone in authority about another person's secrets or wrong actions, or

1.片語動詞及物B2
釋義

to tell someone in authority about another person's secrets or wrong actions, or to break a promise you made to someone

例句

Amara ratted on her brother and told the police where the stolen bikes were hidden.

rat on + person: inform on someone to authorities

Raj promised to help us move, but ratted on the deal at the last minute.

rat on + deal: break an agreement

同義詞
  • tell on

    more common in children's speech; less formal than 'rat on'

  • inform on

    more formal; often used in legal or official contexts

  • go back on

    only covers the promise-breaking meaning, not the informing meaning

文法句型

rat on + [person]

rat on + [promise/agreement/deal]

用法筆記

This phrasal verb has two distinct uses. When the object is a person, it means informing on them to an authority figure. When the object is a deal, promise, or agreement, it means failing to keep your word. The subject is almost always a person, never an institution.

常見錯誤

❌He ratted about his friends to the police.
✅He ratted on his friends to the police.
💡the preposition 'on' is fixed; do not use 'about' or 'against'.
❌She ratted on moving to the new office.
✅She ratted on the plan to move to the new office.
💡the object must be a person or a concrete promise or agreement, not an action.