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Meaning & use

know your stuff

phrase·Everydayinformal

Last updated

UK/ˌnəʊ jɔː ˈstʌf/
US/ˌnoʊ jʊr ˈstʌf/

Meanings

  1. phraseidiominformal

    to be very knowledgeable and skilled in your job or subject

    Grammar: Possessive changes with the subject: I know my stuff, she knows her stuff. Used mainly in the simple present.

    Patterns

    • know your stuff
    • really know your stuff
    • know your stuff about something

    If you want a good mechanic, go to Ray — he really knows his stuff.

    She's only twenty-five, but she knows her stuff and the clients trust her.

    Before you teach the course, make sure you know your stuff.

  2. phraseidiominformal

    to know the specific facts or details needed for a particular task

    Grammar: Often followed by 'when it comes to' or 'on' to name the area: know your stuff on tax law.

    Patterns

    • know your stuff when it comes to something
    • know your stuff on something

    When it comes to repairing old clocks, he knows his stuff.

    You clearly know your stuff on this topic, so I'll leave the decision to you.

Common combinations

really know your stuff
You can tell she really knows her stuff from the way she answers questions.
know your stuff when it comes to something
He knows his stuff when it comes to spreadsheets.
certainly know your stuff
Those guides certainly know their stuff — we learned a lot.
know your stuff inside out
After ten years in the job, she knows her stuff inside out.

Synonyms and how they differ

know what you're doing
A more general phrase about competence in an activity; 'know your stuff' stresses stored knowledge of a subject or job.
be an expert
Stronger and more formal; it suggests recognized authority, while 'know your stuff' just means you are well informed and capable.
know the ropes
Focuses on knowing how things are done in a workplace or system, not on depth of subject knowledge.

Opposites

not know the first thingbe clueless

Word family

know-how noun
Practical knowledge and skill needed to do something.
knowledgeable adjective
Having or showing a lot of knowledge.

Commonly confused: know your stuff or know one's onions?

know your stuff vs know one's onions

An old-fashioned British idiom with a similar meaning; it sounds dated, so 'know your stuff' is the safer, more current choice.

Practice

My new boss has been in publishing for twenty years, so she really ______.

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