ISFvsIssyTell them apart

Which to use

“ISF” and “Issy” are a confusable French pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#17,462
“ISF” frequency rank
#21,670
“Issy” frequency rank
39132
confusion score

Side-by-Side Comparison

Feature ISF Issy
Definition Impôt déclaratif payé par les personnes physiques, célibataires ou en couple, possédant un patrimoine imposable dont la valeur nette est supérieure à un seuil fixé par la loi. Dénomination ancienne ou familière de la commune d’Issy-les-Moulineaux

Where the eye mixes ISF and Issy

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

3 ch
ISF
4 ch
Issy

Visual trap between ISF and Issy

A purely visual mix-up. ISF (\i ɛ.s‿ɛf\) and Issy (\i.si\) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they differ by 1 letter(s) in length. Our composite confusion score for this pair is 39132, derived from the frequency rank of both members and their visual similarity.

ISF is recorded at frequency rank #17,462, classified as aname, pronounced \i ɛ.s‿ɛf\. Issy is at rank #21,670, tagged as aname, pronounced \i.si\.

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 39132, this pair ranks #250,272 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of ISF vs Issy

Shared letters: is. Private to "ISF": f. Private to "Issy": y.

"ISF" · 3 letters · shape VCC  ·  "Issy" · 4 letters · shape VCCV

Known mistypes of this pair

  • Issyissyy · isy · isys · sisy

Frequently Asked Questions

Do "ISF" and "Issy" mean the same thing in a sentence?
No. They are said differently (\i ɛ.s‿ɛf\ versus \i.si\) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
In ordinary French text, does "ISF" or "Issy" show up more?
"ISF" is the more common of the two: it sits at frequency rank #17,462 in our French list, against #21,670 for "Issy". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

  • Full dictionary entry for "ISF" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "Issy" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #250,272 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "ISF" and "Issy" also get mixed up with nearby pairs, the highest-scored neighbour is "isi vs Issy". 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 #250,272 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list