Which to use
“up” is an adverb and “upon” is a preposition - they look or sound alike but fill different roles in a sentence.
- #44
- “up” frequency rank
- #798
- “upon” frequency rank
- 842
- confusion score
Side-by-Side Comparison
| Feature | up | upon |
|---|---|---|
| Definition | Indicating movement towards or location at a higher place or position. | A higher-register or more formal alternative to on in most, though not all, prepositional uses. |
Where the eye mixes up and upon
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Why the eye confuses up with upon
These two trip readers on the page rather than in the ear: up is /ʌp/ while upon is /əˈpɒn/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 extra letter(s) - “up” sits inside “upon”, and the parts of speech differ too (adverb vs preposition), which is usually the fastest check. Our composite confusion score for this pair is 842, derived from the frequency rank of both members and their visual similarity.
up is recorded at frequency rank #44, classified as anadv, pronounced /ʌp/. upon is at rank #798, tagged as aprep, pronounced /əˈpɒn/.
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 842, this pair ranks #528,668 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of up vs upon
Shared letters: pu. Private to "up": -. Private to "upon": no.
"up" · 2 letters · shape VC · "upon" · 4 letters · shape VCVC
Known mistypes of this pair
- upon ← puon · uopn · upno · uponn · uppon
Frequently Asked Questions
Can "up" and "upon" be used interchangeably?
In ordinary English text, does "up" or "upon" show up more?
What to do next
Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.
- Full dictionary entry for "up" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "upon" - compare definitions side by side with the headword page. Word entry
- This pair ranks #528,668 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "up" and "upon" also get mixed up with nearby pairs, the highest-scored neighbour is "UAS vs up". Nearby pair
- Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes
Confusion rank #528,668 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.