o

/ˈəʊ/

//ˈəʊ// character

By · According to Wiktionary data (CC BY-SA) ·

"o" is a 1-letter English headword indexed on PlainSpell.

The verdict

“o” sits in 20 confusable pairs (corpus #790) as a character. The look-alike neighbours are the real trap.

#790
frequency rank, English
15,494
“O” headwords
20
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - The fifteenth letter of the English alphabet, called o and written in the Latin script.

Corpus desk

Index EN-o · o · English

o · rank #790 · 0 variants · 20 confusables

  • FREQ-CORE #790
  • LEN-SHORT 1 letters
  • VOW-1 1 vowel
  • CONFUS-HIGH 20 pairs
  • VAR-0 0 variants
  • BOOK-DENSE 15,494
  • PHOTO-FINISH mom

Nearest frequency peer: mom (-1 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Frequency neighbourhood for “o”

Lower corpus rank = more everyday usage (inverted bar length for readability)

corpus weight

What this shows Bars show where “o” sits against the nearest ranked English headwords in the FrequencyWords band, not a reprint of letter-browse containment.

Source FrequencyWords open word-frequency list As of May 6, 2026

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

o vs of
50% similar
o vs on
50% similar
o vs or
50% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for o
PropertyValue
Headwordo
LanguageEnglish
Part of speechCharacter
IPA/ˈəʊ/
Letters1
Frequency rank#790
Misspellings tracked0
Confusable pairs20
SourceWiktionary (kaikki.org)

Where “o” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). o lands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Easy to mix with look-alikes

The spelling risk for o is neighbouring look-alikes ("of", "on", …), not just typos; it is acharacter pronounced /ˈəʊ/. Frequency #790 among 15,494 “O” headwords. 2 recorded senses keep meaning in play.

Zero misspellings are on record for o in our index, which points to an orthography that plays by predictable English rules. It also participates in 20 confusable-pair relationships, "of", "on", "or", and more, since the words sound or look close enough that writers reach for the wrong one mid-sentence.

This entry carries no recorded etymology, leaving phoneme-to-grapheme mapping as the best guide to its spelling rather than a borrowing history. The correct English form is o, spelled O.

Definition

  1. 1
    The fifteenth letter of the English alphabet, called o and written in the Latin script.
  2. 2
    Alternative form of ο, the fifteenth letter of the Classical and Modern Greek alphabets, called omicron and (astronomy) used as an abbreviation of omicron in star names.

Recorded use

Wiktionary example

These source excerpts show how o appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. The system's Bayer designation is o Persei.

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

PlainSpell is rendered directly from structured Wiktionary extracts and open word-frequency lists, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 6, 2026. Primary sources: Wiktionary (via kaikki.org) and FrequencyWords.

Frequently Asked Questions

How do you spell "o"?
"o" is spelled O. The IPA pronunciation is /ˈəʊ/.
What does "o" mean?
As a character, "o" means: The fifteenth letter of the English alphabet, called o and written in the Latin script.
What words are commonly confused with "o"?
"o" is commonly confused with "of", "on", "or". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "o"?
The IPA (International Phonetic Alphabet) transcription for "o" is /ˈəʊ/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What language does "o" come from?
"o" is a English word. PlainSpell covers definitions, pronunciations, and spelling data across English, Spanish, Portuguese, French, and German.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.
Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

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

Source: FrequencyWords open word-frequency list