Which to use
“idem” is an adverb and “ides” is a noun - they look or sound alike but fill different roles in a sentence.
- #6,513
- “idem” frequency rank
- #42,389
- “ides” frequency rank
- 48902
- confusion score
Side-by-Side Comparison
| Feature | idem | ides |
|---|---|---|
| Definition | De même, pareillement. On l’emploie pour éviter de répéter ce qui vient d’être dit ou écrit. | Le quinzième jour des mois de mars, de mai, de juillet et d’octobre dans le calendrier des anciens Romains, et le treizième des autres mois. |
Where the spellings diverge
Shared letters are muted; the letters that actually set idem and ides apart are highlighted. They share 3 letters in sequence, which is exactly why the eye skips the difference.
Spelling & Dictionary Insight
These two trip readers on the page rather than in the ear: idem is \i.dɛm\ while ides is \id\. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - m in “idem” becomes s in “ides”, and the parts of speech differ too (adverb vs noun), which is usually the fastest check. Our composite confusion score for this pair is 48902, derived from the frequency rank of both members and their visual similarity.
idem is recorded at frequency rank #6,513, classified as anadv, pronounced \i.dɛm\. ides is at rank #42,389, tagged as anoun, pronounced \id\.
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 48902, this pair ranks #175,127 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of idem vs ides
Shared letters: dei. Private to "idem": m. Private to "ides": s.
"idem" · 4 letters · shape VCVC · "ides" · 4 letters · shape VCVC
Known mistypes of this pair
Frequency comparison
Frequently Asked Questions
Can "idem" and "ides" be used interchangeably?
Which is more common, "idem" or "ides"?
Remembering idem vs ides
The fastest way to pick the right one every time.
- Check the role first: if you need an adverb, it's “idem”; for a noun, it's “ides”.
- See each word in full, definition, IPA, etymology and its other confusables. Full “idem” entry
- Browse more pairs most likely to be confused. Most confusable