a fine line — narrow boundary (between two similar things)
collocationC1IELTS 7+neutralcommon
used to say that two things are very similar or close together, so it is difficult to see the difference between them, especially when one is positive and the other is negative
Say it like a native
Textbook There is a very small difference between confidence and arrogance.
Native There's a fine line between confidence and arrogance.
'A fine line between X and Y' is the idiom; the paraphrase loses the 'easy to cross' nuance.
Pattern: there is a fine line between A and B
In use
- There’s a fine line between being confident and coming across as arrogant.daily life
- In my opinion, there’s a fine line between encouraging children to work hard and overwhelming them with unrealistic expectations.IELTS speaking
Common mistake
✗ There's a fine line of being honest and being rude.
✓ There's a fine line between being honest and being rude.
'A fine line BETWEEN X and Y', not 'of'.
Common collocations
a fine line between X and Y— between, tread, walk, cross
Don't confuse it
This is not about a literal line or a physical boundary; it’s a figurative way to talk about how two things can be almost the same, but not quite.