femvsfiWhat's the difference?

Quick tell: fem is a num, fi is a noun, so they fill different roles in a sentence.

Which to use

“fem” is a num and “fi” is a noun - they look or sound alike but fill different roles in a sentence.

#41,915
“fem” frequency rank
#6,305
“fi” frequency rank
48220
confusion score

Side-by-Side Comparison

Feature fem fi
Definition Cinco. Vigésima primera letra del alfabeto griego (Φ, φ), que se convierte en ph en el alfabeto latino y en f y también en ph en las lenguas derivadas del latín.

Where the eye mixes fem and fi

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

3 ch
fem
2 ch
fi

Visual trap between fem and fi

These two trip readers on the page rather than in the ear: fem is [fɛmˀ] while fi is [ˈfi]. 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 (num vs noun), which is usually the fastest check. Our composite confusion score for this pair is 48220, derived from the frequency rank of both members and their visual similarity.

fem is recorded at frequency rank #41,915, classified as anum, pronounced [fɛmˀ]. fi is at rank #6,305, tagged as anoun, pronounced [ˈfi].

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 48220, this pair ranks #115,703 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of fem vs fi

Shared letters: f. Private to "fem": em. Private to "fi": i.

"fem" · 3 letters · shape CVC  ·  "fi" · 2 letters · shape CV

Frequently Asked Questions

Is swapping "fem" for "fi" ever safe?
No - they are not even the same part of speech. "fem" is a num and "fi" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "fem" or "fi"?
"fi" is the more common of the two: it sits at frequency rank #6,305 in our Spanish list, against #41,915 for "fem". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Eye-level mix-up between "fem" and "fi" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "fem" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "fi" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #115,703 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "fem" and "fi" also get mixed up with nearby pairs, the highest-scored neighbour is "fem vs fuer". Nearby pair

Confusion rank #115,703 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list