brush up

practise something again to improve a skill you have not used recently

B2

What does "brush up on sth" mean?

Brushing up on something means going back to a skill or area of knowledge you already have some experience with, but haven't used for a while, so it has become a little rusty. The idea is not that you are learning from zero, but that you are polishing and refreshing what is already there. It is commonly used when someone is preparing for a specific situation — a job interview, a trip abroad, or returning to a subject after a long break. For example, someone who studied French at school but rarely uses it might brush up on their French before a holiday in Paris. The phrase has a practical, goal-oriented feel, and works equally well in everyday conversation and more formal contexts like professional emails or career advice.

Examples

How to use it

brush up on + noun/noun phrase

The most common pattern — the object (a skill, language, or area of knowledge) always follows directly after 'on'.

I should brush up on my grammar before the writing assessment.

brush up on + pronoun (it/them)

When the skill has already been mentioned, a pronoun can replace the noun — it always stays after 'on'.

My presentation skills are a bit rusty — I need to brush up on them before Monday.

modal + brush up on + noun

Very common with modals like 'should', 'need to', 'want to', and 'ought to', often expressing a plan or intention.

You really should brush up on your knowledge of current events before the debate.

brush up (without object)

The 'on' and its object can be dropped when the subject has already been made clear in conversation or writing.

My German used to be decent — I just need to brush up a little before the conference.

present perfect: have/has + brushed up on + noun

Often used to report that preparation is complete, especially in professional or goal-oriented contexts.

She's brushed up on her negotiation skills since her last round of interviews.

Common Collocations

brush up on your language skillsbrush up on your grammarbrush up on the basicsbrush up on your knowledgebrush up on your French/Spanish/etc.brush up on interview techniques

Common Mistakes

Missing 'on' — object placed directly after 'up'

Learners often drop 'on' and place the object straight after 'up', but this is incorrect. The preposition 'on' is always required before the object.

✗ I need to brush up my Spanish before the trip.
✓ I need to brush up on my Spanish before the trip.
Using it for something never previously learned

'Brush up on' only works when you already have some knowledge of the subject that has simply become rusty. If you have never studied something before, use 'learn' instead.

✗ I've never studied coding, but I want to brush up on it.
✓ I've never studied coding, but I want to learn it.
Confusing 'brush up on' with 'catch up on'

'Brush up on' is about refreshing a skill that has gone rusty, while 'catch up on' means dealing with things you have missed or fallen behind on — such as unread emails or missed episodes of a series.

✗ I missed three weeks of classes, so I need to brush up on what I missed.
✓ I missed three weeks of classes, so I need to catch up on what I missed.

Usage

This phrasal verb is neutral in register and works equally well in spoken and written English. It always implies refreshing existing knowledge, not learning something for the first time — if you've never studied something before, use 'learn' instead.

Frequently Asked Questions

Can I use 'brush up on' for a skill I learned a long time ago but barely remember?

Yes, as long as you have some prior experience with it, even if it feels very faint. The phrase implies the knowledge is there somewhere but has become rusty — even quite deeply rusty. However, if you have genuinely never studied the subject at all, 'brush up on' would sound unnatural and you should use 'learn' instead.

What kinds of things can you 'brush up on'?

The phrase is most commonly used with languages (brush up on your Italian), academic subjects (brush up on your maths), professional skills (brush up on your presentation skills or interview techniques), and practical abilities (brush up on your driving). It works with almost any skill or area of knowledge that someone might have let slide over time.

Can 'brush up on' be used in the passive, like 'my skills were brushed up on'?

No — this construction sounds very unnatural in English. 'Brush up on' is always used actively, with a person as the subject refreshing their own skills or knowledge. There is no natural passive form.

Does 'brush up on' suggest a lot of studying or just a quick review?

It generally suggests a lighter, refresher-style review rather than deep or intensive study. The idea is more about polishing something you already know than sitting down for serious cramming. If you want to suggest intensive study, especially before an exam, 'swot up on' (in British English) would carry that stronger sense.

Is 'brush up on' used mainly in British or American English?

It is used naturally in both British and American English, and there is no strong regional preference. You will encounter it comfortably on both sides of the Atlantic in everyday conversation, professional writing, and learning contexts.

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