Which to use
“underlining” is a verb and “underpinning” is a noun - they look or sound alike but fill different roles in a sentence.
- #42,468
- “underlining” frequency rank
- #33,896
- “underpinning” frequency rank
- 76364
- confusion score
Side-by-Side Comparison
| Feature | underlining | underpinning |
|---|---|---|
| Definition | present participle and gerund of underline | A support or foundation, especially as a structure of masonry that supports a wall. |
Where the spellings diverge
Shared letters are muted; the letters that actually set underlining and underpinning apart are highlighted. They share 10 letters in sequence, which is exactly why the eye skips the difference.
Spelling & Dictionary Insight
underlining and underpinning form a confusable pair in the English index, two distinct headwords that are easily confused because they look alike, sound alike, or both. They differ by 1 letter(s) in length - close enough that the eye skips over the difference, far enough that meaning fully diverges. Our composite confusion score for this pair is 76364, derived from the frequency rank of both members and their visual similarity.
underlining is recorded at frequency rank #42,468, classified as averb. underpinning is at rank #33,896, tagged as anoun.
Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.
With a confusion score of 76364, this pair ranks #30,338 of 530,003 scored English confusable pairs - among the most confusable pairs.
Frequency comparison
Frequently Asked Questions
Can "underlining" and "underpinning" be used interchangeably?
Remembering underlining vs underpinning
The fastest way to pick the right one every time.
- Check the role first: if you need a verb, it's “underlining”; for a noun, it's “underpinning”.
- See each word in full, definition, IPA, etymology and its other confusables. Full “underlining” entry
- Browse more pairs most likely to be confused. Most confusable