Grammar fix
pop up
appear suddenly on screen
when a window, message or notification appears suddenly on your screen
phrasal verbB1core
Hear it in context
Notice where the phrase sounds natural.
A message popped up saying my storage was full.
These ads keep popping up and I can't close them.
Fix the pattern
One small grammar move makes it sound right.
Don't say 'a window appeared up' — it 'popped up' or 'a pop-up appeared'.