ob vs Ost, What's the Difference?

Which to use

“ob” is a pronoun and “Ost” is a noun - they look or sound alike but fill different roles in a sentence.

#28,692
“ob” frequency rank: #27,958
“Ost” frequency rank: 56650
confusion score

Side-by-Side Comparison

Feature	ob	Ost
Definition	eu, pronome pessoal do caso nominativo da primeira pessoa do singular;	leste

Where the eye mixes ob and Ost

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

2 ch

3 ch

Ost

Visual trap between ob and Ost

These two trip readers on the page rather than in the ear: ob is /ob/ while Ost is /ɔst/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (pronoun vs noun), which is usually the fastest check. Our composite confusion score for this pair is 56650, derived from the frequency rank of both members and their visual similarity.

ob is recorded at frequency rank #28,692, classified as apron, pronounced /ob/. Ost is at rank #27,958, tagged as anoun, pronounced /ɔst/.

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 56650, this pair ranks #9,830 of 75,631 scored Portuguese confusable pairs - among the most confusable pairs.

Orthographic DNA of ob vs Ost

Shared letters: o. Private to "ob": b. Private to "Ost": st.

"ob" · 2 letters · shape VC · "Ost" · 3 letters · shape VCC

Frequently Asked Questions

Can "ob" and "Ost" be used interchangeably?

No - they are not even the same part of speech. "ob" is a pronoun and "Ost" a noun, so a sentence built for one is usually ungrammatical with the other.

In ordinary Portuguese text, does "ob" or "Ost" show up more?

"Ost" is the more common of the two: it sits at frequency rank #27,958 in our Portuguese list, against #28,692 for "ob". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

Full dictionary entry for "ob" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "Ost" - compare definitions side by side with the headword page. Word entry
This pair ranks #9,830 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
"ob" and "Ost" also get mixed up with nearby pairs, the highest-scored neighbour is "ob vs oni". Nearby pair

Confusion rank #9,830 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.