rádiovsrápidoWhat's the difference?

Quick tell: rádio is a noun, rápido is an adjective, so they fill different roles in a sentence.

Which to use

“rádio” is a noun and “rápido” is an adjective - they look or sound alike but fill different roles in a sentence.

#857
“rádio” frequency rank
#811
“rápido” frequency rank
1668
confusion score

Side-by-Side Comparison

Feature rádio rápido
Definition elemento químico de símbolo Ra, possui o número atômico 88 e massa atômica relativa 226,025 u; é um metal alcalino terroso, branco prateado, altamente radioativo; ocorre em todos os minérios de urânio, e é produzido por decaimento radioativo; é utilizado na medicina para tratamento de câncer e, em laboratórios, como fonte de neutrons para análise de materiais que anda depressa

Letter map: rádio vs rápido

Shared letters muted; letters that set rádio and rápido apart highlighted. Shared run: 4. rádio runs 5 letters (CVCVV) against rápido's 6 (CVCVCV) - the length gap alone is often enough to separate them once you know to check it.

5 ch
rádio
6 ch
rápido

Role in the sentence - rádio and rápido

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: rádio is anoun and rápidoanadjective. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 1668, derived from the frequency rank of both members and their visual similarity.

rádio is recorded at frequency rank #857, classified as anoun. rápido is at rank #811, tagged as anadj, pronounced /ˈRa.pi.du/.

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 1668, this pair ranks #73,853 of 75,631 scored Portuguese confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of rádio vs rápido

Shared letters: diorá. Private to "rádio": -. Private to "rápido": p.

"rádio" · 5 letters · shape CVCVV  ·  "rápido" · 6 letters · shape CVCVCV

Frequently Asked Questions

Can "rádio" and "rápido" be used interchangeably?
No - they are not even the same part of speech. "rádio" is a noun and "rápido" an adjective, so a sentence built for one is usually ungrammatical with the other.
In ordinary Portuguese text, does "rádio" or "rápido" show up more?
"rápido" is the more common of the two: it sits at frequency rank #811 in our Portuguese list, against #857 for "rádio". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

You've compared "rádio" and "rápido". Here's where to go from here.

  • Full dictionary entry for "rádio" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "rápido" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #73,853 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "rádio" and "rápido" also get mixed up with nearby pairs, the highest-scored neighbour is "rabi vs rádio". Nearby pair

Confusion rank #73,853 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list