not to mention — additionally emphasising
expressionC1IELTS 7+neutraloccasional
Used to introduce extra information that makes your point even stronger, often highlighting something important or impressive in addition to what was just said.
Say it like a native
Textbook In addition to the aforementioned, one should also consider the cost.
Native It's slow — not to mention expensive.
The chunk adds a clinching point with punch; 'in addition to the aforementioned' is heavy.
Pattern: [main point], not to mention [additional point]
In use
- The new job offers a great salary, not to mention flexible working hours.daily life
- There are many benefits to studying abroad, such as improving language skills, not to mention gaining a deeper understanding of different cultures.IELTS speaking
Common mistake
✗ The trip was long, not mention expensive.
✓ The trip was long, not to mention expensive.
Fixed phrase 'not TO mention' — don't drop 'to'.
Common collocations
not to mention— not to mention the, not to mention that, , not to mention
Don't confuse it
'Not to mention' adds extra emphasis, while 'let alone' is used to highlight something even less likely or more extreme.