thirty

/ˈθɜːti/

//ˈθɜːti// num

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

"thirty" is a 6-letter English headword indexed on PlainSpell.

The verdict

“thirty” is a regularly-used English word, ranked #3,791 in English word frequency and used as a numeral.

#3,791
frequency rank, English
6
letters
10
tracked misspellings
11
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - The cardinal number occurring after twenty-nine and before thirty-one, represented in Arabic numerals as 30.

Visual similarity to commonly confused words

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

thirty vs titty
67% similar
thirty vs thorny
67% similar
thirty vs twisty
67% similar

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

Key facts for thirty
PropertyValue
Headwordthirty
LanguageEnglish
Part of speechNumeral
IPA/ˈθɜːti/
Letters6
Frequency rank#3,791
Misspellings tracked10
Confusable pairs11
SourceWiktionary (kaikki.org)

Where “thirty” 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). thirty 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 thirty is 6 letters long, classified as a numeral, and transcribed in the International Phonetic Alphabet as /ˈθɜːti/. Corpus data places it at rank #3,791 in overall English word frequency, indicating it appears regularly in written and spoken text. The dominant gloss from Wiktionary reads: "The cardinal number occurring after twenty-nine and before thirty-one, represented in Arabic numerals as 30.".

Our generated misspelling index lists 10 likely wrong-spelling variants for thirty, with forms such as "htirty", "thhirty", and "thirrty". Each variant is a distinct typo pattern an edit-distance generator flags, typically a doubled-consonant error, a silent-letter drop, or a vowel substitution. It also participates in 11 confusable-pair relationships, "titty", "thorny", "twisty", and more, a pairing that trips writers up because the two words share enough sound or shape to blur together.

Etymologically, the entry records: From Middle English thirty, metathetic alternant of Middle English thriti, þrittiȝ, from Old English þrītiġ (“thirty”), from Proto-Germanic *þrīz tigiwiz (“thirty”, literally “three tens”), equivalent to three + -ty. Cognate with Scots therty, tretty (“thir… The correct English form is thirty, spelled T-H-I-R-T-Y.

Definition

  1. 1
    The cardinal number occurring after twenty-nine and before thirty-one, represented in Arabic numerals as 30.

Etymology

From Middle English thirty, metathetic alternant of Middle English thriti, þrittiȝ, from Old English þrītiġ (“thirty”), from Proto-Germanic *þrīz tigiwiz (“thirty”, literally “three tens”), equivalent to three + -ty. Cognate with Scots therty, tretty (“thirty”), West Frisian tritich (“thirty”), Dutch dertig (“thirty”), German dreißig (“thirty”).

This word in other languages

treinta(Español)trente(Français)dreißig(Deutsch)trinta(Português)

Common misspellings

Also misspelled as: htirty,thhirty,thirrty,thirtty,thirtyy,thiryt,thitry,thrity,tihrty,tthirty

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of thirty - expressed in single-character edits (insert, delete, or swap one letter). Bigger bars stand out at a glance; a one-edit slip is the hardest to catch.

htirty2thhirty1thirrty1thirtty1thirtyy1thiryt2thitry2thrity2
Edit distance from "thirty"

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 "thirty"?
"thirty" is spelled T-H-I-R-T-Y. The IPA pronunciation is /ˈθɜːti/.
What does "thirty" mean?
As a numeral, "thirty" means: The cardinal number occurring after twenty-nine and before thirty-one, represented in Arabic numerals as 30.
What words are commonly confused with "thirty"?
"thirty" is commonly confused with "titty", "thorny", "twisty". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "thirty"?
The IPA (International Phonetic Alphabet) transcription for "thirty" is /ˈθɜːti/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "thirty"?
From Middle English thirty, metathetic alternant of Middle English thriti, þrittiȝ, from Old English þrītiġ (“thirty”), from Proto-Germanic *þrīz tigiwiz (“thirty”, literally “three tens”), equivalent to three + -ty. Cognate with Scots therty, tre... See the full etymology section above for more details.
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 “thirty”

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

  • The one correct English spelling is T-H-I-R-T-Y - every other letter order is a misspelling in standard orthography.
  • Say it as /ˈθɜːti/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Don't mix it up with “titty” - see the side-by-side comparison. thirty vs titty
  • 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