Grammar fix
rock up
arrive casually
To arrive somewhere in a very casual way, sometimes without arranging it first.
phrasal verb
How oftenNow and then
LevelB2
Used inMostly spoken
Hear it in context
Notice where the phrase sounds natural.
A few friends rocked up at my flat after work, so I ordered some pizza.
My cousins sometimes rock up at our house without warning, but we usually have enough food for everyone.
Fix the pattern
One small grammar move makes it sound right.
Not: He rocked up on the party two hours late.
Say: He rocked up at the party two hours late.
Use 'at' or 'to' for a place or event, not 'on'; this phrase is mainly British and Australian, while US English more often uses 'show up'.
Don't confuse it
Other ways to say it
Arrive at a place or event
How formalVery casualNeutral
rock upYou're here · Very casual, especially British or Australian: arrive somewhere.
show upInformal: arrive or attend, especially when someone expects you.turn upEspecially British: arrive, sometimes unexpectedly or late.