Which to use
“perf” is an adjective and “PF” is a noun - they look or sound alike but fill different roles in a sentence.
- #42,815
- “perf” frequency rank
- #16,301
- “PF” frequency rank
- 59116
- confusion score
Side-by-Side Comparison
| Feature | perf | PF |
|---|---|---|
| Definition | Abbreviation of perforated; when followed by a number, eg, perf 14, this indicates the number of perforations per two centimetres. | Initialism of pilot flying, a pilot currently in control of the flight trajectory of the aircraft, as opposed to pilot monitoring. |
Letter map: perf vs PF
Shared letters muted; letters that set perf and PF apart highlighted. Shared run: 2.
Grammar separator: perf vs PF
Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: perf is anadjective and PFanoun. On the page they differ by 2 letter(s) in length. Our composite confusion score for this pair is 59116, derived from the frequency rank of both members and their visual similarity.
perf is recorded at frequency rank #42,815, classified as anadj, pronounced /pɜː(ɹ)f/. PF is at rank #16,301, 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 59116, this pair ranks #108,209 of 530,003 scored English confusable pairs - among the most confusable pairs.
Orthographic DNA of perf vs PF
Shared letters: fp. Private to "perf": er. Private to "PF": -.
"perf" · 4 letters · shape CVCC · "PF" · 2 letters · shape CC
Known mistypes of this pair
- perf ← eprf · pefr · perff · perrf · pperf · pref
Frequently Asked Questions
Do "perf" and "PF" mean the same thing in a sentence?
Frequency check: "perf" vs "PF" - which ranks higher?
Useful next steps
Done with this confusable. These links stay specific to "perf" and "PF".
- Full dictionary entry for "perf" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "PF" - compare definitions side by side with the headword page. Word entry
- This pair ranks #108,209 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "perf" and "PF" also get mixed up with nearby pairs, the highest-scored neighbour is "pecs vs perf". 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 #108,209 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.