o'svsOSWhat's the difference?

Quick tell: o's is a noun, OS is a name, so they fill different roles in a sentence.

Which to use

“o's” is a noun and “OS” is a name - they look or sound alike but fill different roles in a sentence.

#30,902
“o's” frequency rank
#6,077
“OS” frequency rank
36979
confusion score

Side-by-Side Comparison

Feature o's OS
Definition plural of the letter o Initialism of Owen Sound.

Where the eye mixes o's and OS

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

3 ch
o's
2 ch
OS

Spelling & Dictionary Insight

These two trip readers on the page rather than in the ear: o's is /əʊz/ while OS is /ˌoʊ ˈɛs/. 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 (noun vs name), which is usually the fastest check. Our composite confusion score for this pair is 36979, derived from the frequency rank of both members and their visual similarity.

o's is recorded at frequency rank #30,902, classified as anoun, pronounced /əʊz/. OS is at rank #6,077, tagged as aname, pronounced /ˌoʊ ˈɛs/.

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 36979, this pair ranks #298,464 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of o's vs OS

Shared letters: os. Private to "o's": -. Private to "OS": -.

"o's" · 2 letters · shape VC  ·  "OS" · 2 letters · shape VC

Frequently Asked Questions

Can "o's" and "OS" be used interchangeably?
No - they are not even the same part of speech. "o's" is a noun and "OS" a name, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "o's" or "OS"?
"OS" is the more common of the two: it sits at frequency rank #6,077 in our English list, against #30,902 for "o's". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

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

Source: FrequencyWords open word-frequency list