build up — increase gradually
phrasal verbB1IELTS 5+neutralcommon
To make something become larger or greater over time, often slowly.
Say it like a native
Textbook A considerable accumulation of dust has gradually formed.
Native Dust builds up if you don't clean.
'A considerable accumulation has gradually formed' is heavy; 'builds up' is natural.
Pattern: build up (something) / build (something) up
In use
- If you save a little money each month, your savings will build up over time.daily life
- During the exam period, stress can build up if you don't take breaks.IELTS speaking
Common mistake
✗ Pressure builds up slowly over the time.
✓ Pressure builds up slowly over time.
'Over time' — no 'the'.
Common collocations
build up + over time— over time, gradually, pressure, slowly
Don't confuse it
Not the same as 'increase suddenly' or 'explode'.
Related
- build up (develop strength or confidence) — Another meaning of 'build up' is 'develop strength or confidence'; compare the examples to keep the meanings separate.