Which to use
“fifth” is an adjective and “forth” is an adverb - they look or sound alike but fill different roles in a sentence.
- #1,719
- “fifth” frequency rank
- #3,625
- “forth” frequency rank
- 5344
- confusion score
Side-by-Side Comparison
| Feature | fifth | forth |
|---|---|---|
| Definition | The ordinal form of the number five. | Forward in time, place or degree. |
Where the eye mixes fifth and forth
Muted = shared; highlighted = the visual trap. They share 3 letters in sequence.
Visual trap between fifth and forth
These two trip readers on the page rather than in the ear: fifth is /fɪfθ/ while forth is /fɔːθ/. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (adjective vs adverb), which is usually the fastest check. Our composite confusion score for this pair is 5344, derived from the frequency rank of both members and their visual similarity.
fifth is recorded at frequency rank #1,719, classified as anadj, pronounced /fɪfθ/. forth is at rank #3,625, tagged as anadv, pronounced /fɔːθ/.
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 5344, this pair ranks #515,683 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of fifth vs forth
Shared letters: fht. Private to "fifth": i. Private to "forth": or.
"fifth" · 5 letters · shape CVCCC · "forth" · 5 letters · shape CVCCC
Known mistypes of this pair
Frequently Asked Questions
Is swapping "fifth" for "forth" ever safe?
In ordinary English text, does "fifth" or "forth" show up more?
Useful next steps
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "fifth" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "forth" - compare definitions side by side with the headword page. Word entry
- This pair ranks #515,683 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "fifth" and "forth" also get mixed up with nearby pairs, the highest-scored neighbour is "foh vs forth". 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 #515,683 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.