Phrase · B2 · Neutral to informal · common for study and preparation
brush up on
Refresh or improve knowledge or a skill you learned before by reviewing or practicing it.
obnoviti znanje; podsetiti se i uvežbati ranije naučeno

Memory scene
Brush the dust off an old study book: you uncover knowledge that was already there.
How it sounds
brush UP ahn
Stress up; link on lightly to the subject or skill that follows.
Build the sentence
brush up on + subject/skill · brush up on it
Use it
I’m brushing up on my spreadsheet skills before starting the new job.
The speaker already has some knowledge and wants to refresh it.
It has been years since I studied fractions, so I brushed up on them before helping my son.
Keep the pronoun after on in this three-word pattern.
Watch out
This usually means refreshing existing knowledge, not learning from zero. Keep on in the pattern taught here: brush up on it, not brush it up on. Brush up your French is also possible, but follows a different two-word pattern.
Nearby language
States the same goal directly and sounds slightly more formal.
Means begin without previous knowledge rather than refresh it.
Means review material, without necessarily implying a skill has become rusty.
Make it yours
Ponovo ćete držati prezentacije na engleskom posle duge pauze i želite da obnovite veštinu.