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” is in the everyday core of English, ranked #790 in English word frequency and used as a character.

#790
frequency rank, English
1
letter
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.

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.

Spelling & Dictionary Insight

The English entry for o is 1 letters long, classified as a character, and transcribed in the International Phonetic Alphabet as /ˈəʊ/. Corpus data places it at rank #790 in overall English word frequency, putting it firmly in the everyday core of the language. Wiktionary records 2 distinct senses for this headword, so context determines which meaning a reader should apply.

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.

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.

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.

Using “o”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is O - every other letter order is a misspelling in standard orthography.
  • Say it as /ˈəʊ/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Don't mix it up with “of” - see the side-by-side comparison. o vs of
  • Browse more English words and confusable pairs in the same reference. English words
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 FrequencyWords open word-frequency list