Grass on/up – English Phrasal Verb – Online English Lessons

To grass on somebody, or grass up somebody (or grass somebody up) is to tell someone in authority, especially the police, about something bad that somebody has done.

Informal British / UK English.

grass (verb) to tell the police about something that somebody has done wrong.

grass (noun) a police informer. British/UK English.

Examples of use:

1. She grassed on us to the local police.

2. Which one of you grassed me up to the police?!

3. Please don’t grass him up – he won’t do it again.

infinitive grass on/up
present simple grass on/up and grasses on/up
-ing form grassing on/up
past simple grassed on/up
past participle grassed on/up

Practise your English and write your own sentence using ‘grass on’ or ‘grass up’

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