rexvsríoWhich spelling fits?

Which to use

“rex” and “río” are a confusable Spanish pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#13,343
“rex” frequency rank
#698
“río” frequency rank
14041
confusion score

Side-by-Side Comparison

Feature rex río
Definition Rey, monarca. Corriente de agua de caudal importante que discurre por tierra desde un manantial, una masa de hielos o un lago.

Where the eye mixes rex and río

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

3 ch
rex
3 ch
río

Why the eye confuses rex with río

A purely visual mix-up. rex (/ˈreːks/) and río ([ˈrio]) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 14041, derived from the frequency rank of both members and their visual similarity.

rex is recorded at frequency rank #13,343, classified as anoun, pronounced /ˈreːks/. río is at rank #698, tagged as anoun, pronounced [ˈrio].

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 14041, this pair ranks #285,622 of 323,831 scored Spanish confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of rex vs río

Shared letters: r. Private to "rex": ex. Private to "río": .

"rex" · 3 letters · shape CVC  ·  "río" · 3 letters · shape CVV

Frequently Asked Questions

Can "rex" and "río" be used interchangeably?
No. They are said differently (/ˈreːks/ versus [ˈrio]) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Frequency check: "rex" vs "río" - which ranks higher?
"río" is the more common of the two: it sits at frequency rank #698 in our Spanish list, against #13,343 for "rex". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

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

  • Full dictionary entry for "rex" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "río" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #285,622 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "rex" and "río" also get mixed up with nearby pairs, the highest-scored neighbour is "rema vs rex". Nearby pair

Confusion rank #285,622 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