masvsmauWhich spelling fits?

Quick tell: mas is a conjunction, mau is an adjective, so they fill different roles in a sentence.

Which to use

“mas” is a conjunction and “mau” is an adjective - they look or sound alike but fill different roles in a sentence.

#25
“mas” frequency rank
#1,936
“mau” frequency rank
1961
confusion score

Side-by-Side Comparison

Feature mas mau
Definition conjunção adversativa, indica clara oposição entre ideias que não é de boa qualidade, ruim

Where the eye mixes mas and mau

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

3 ch
mas
3 ch
mau

Look-alike desk: mas vs mau

These two trip readers on the page rather than in the ear: mas is /ˈmɐʃ/ while mau is /ˈmaw/. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - s in “mas” becomes u in “mau”, and the parts of speech differ too (conjunction vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 1961, derived from the frequency rank of both members and their visual similarity.

mas is recorded at frequency rank #25, classified as aconj, pronounced /ˈmɐʃ/. mau is at rank #1,936, tagged as anadj, pronounced /ˈmaw/.

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 1961, this pair ranks #73,555 of 75,631 scored Portuguese confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of mas vs mau

Shared letters: am. Private to "mas": s. Private to "mau": u.

"mas" · 3 letters · shape CVC  ·  "mau" · 3 letters · shape CVV

Frequently Asked Questions

Do "mas" and "mau" mean the same thing in a sentence?
No - they are not even the same part of speech. "mas" is a conjunction and "mau" an adjective, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "mas" vs "mau" - which ranks higher?
"mas" is the more common of the two: it sits at frequency rank #25 in our Portuguese list, against #1,936 for "mau". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

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 "mas" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "mau" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #73,555 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "mas" and "mau" also get mixed up with nearby pairs, the highest-scored neighbour is "maa vs mau". Nearby pair

Confusion rank #73,555 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