a fundamental difference — basic and important distinction
a very basic and important difference between two things, often used to highlight that they are not just slightly different, but different in a way that really matters.
Say it like a native
Textbook There exists a fundamental difference between the two approaches.
Native There's a fundamental difference between the two.
'There exists' is stilted; in speech natives just say 'there's'.
Pattern: there is/was a fundamental difference (between A and B) | a fundamental difference in/with/regarding something
In use
- There is a fundamental difference between knowing about something and truly understanding it.society
- In my opinion, there is a fundamental difference between simply memorising facts and developing critical thinking skills, which is why education systems should focus more on the latter.IELTS speaking
Common mistake
✗ There is a fundamental difference of the two methods.
✓ There is a fundamental difference between the two methods.
'Difference BETWEEN X and Y', not 'of'.
Common collocations
a fundamental difference between— the two, them, approaches, in how
Don't confuse it
Unlike 'a big difference' (which can refer to size or amount), 'a fundamental difference' means the things are different at a basic or essential level, not just superficially.