Which to use
“false” is an adjective and “fast” is an adverb - they look or sound alike but fill different roles in a sentence.
- #23,516
- “false” frequency rank
- #243
- “fast” frequency rank
- 23759
- confusion score
Side-by-Side Comparison
| Feature | false | fast |
|---|---|---|
| Definition | falsch | nicht ganz |
Where the eye mixes false and fast
Muted = shared; highlighted = the visual trap. They share 3 letters in sequence.
Why the eye confuses false with fast
These two trip readers on the page rather than in the ear: false is [fɔːls] while fast is [fast]. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (adjective vs adverb), which is usually the fastest check. Our composite confusion score for this pair is 23759, derived from the frequency rank of both members and their visual similarity.
false is recorded at frequency rank #23,516, classified as anadj, pronounced [fɔːls]. fast is at rank #243, tagged as anadv, pronounced [fast].
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 23759, this pair ranks #1,856,961 of 2,006,359 scored German confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of false vs fast
Shared letters: afs. Private to "false": el. Private to "fast": t.
"false" · 5 letters · shape CVCCV · "fast" · 4 letters · shape CVCC
Known mistypes of this pair
Frequently Asked Questions
Can "false" and "fast" be used interchangeably?
Frequency check: "false" vs "fast" - which ranks higher?
After this comparison
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "false" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "fast" - compare definitions side by side with the headword page. Word entry
- This pair ranks #1,856,961 of 2,006,359 scored German confusable pairs in this corpus vintage. Corpus statistics
- "false" and "fast" also get mixed up with nearby pairs, the highest-scored neighbour is "false vs fils". 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 #1,856,961 of 2,006,359 scored German pairs, corpus vintage 2026-09-03, not spelling advice.