thirty
Thirty (num) means the number after twenty-nine and before thirty-one; 30. Example: “He turned thirty last week.”
How to use thirty
Learner’s notesIn plain EnglishThe number 30.
Word forms
thirties plural
Fill the gap
Can you complete this real example?
He turned _____ last week.
Etymology
From Old English þrītiġ, literally "three tens".
Rhymes for thirty
See all rhymes for thirty →Frequently asked questions
What does “thirty” mean?
The word “thirty” means the number after twenty-nine and before thirty-one; 30. In plain terms, the number 30.
How do you pronounce “thirty”?
“Thirty” is pronounced THUR-tee (/ˈθɝti/ in IPA).
How do you use “thirty” in a sentence?
Here is “thirty” used in a sentence: “He turned thirty last week.”
What part of speech is “thirty”?
“Thirty” is a num.
Where does the word “thirty” come from?
The word “thirty” comes from Old English. From Old English þrītiġ, literally "three tens".
Is “thirty” a common word?
“Thirty” is a fairly common word in modern English, usually learned at around the A1 level.
How do you spell thirty correctly?
The correct spelling is thirty, with i-r before the t. Common misspellings include "thirthy" and "thrity." Note the vowel change from three: the tens form is thirty, just as three gives thirteen.
Are numbers like thirty one hyphenated?
Yes. Compound numbers from twenty-one to ninety-nine are hyphenated when written out, so the forms are thirty-one, thirty-two, and so on up to thirty-nine. Thirty itself, as a round number, takes no hyphen.
What is the difference between thirty and thirtieth?
Thirty is the cardinal number 30, used for counting: "thirty days." Thirtieth is the ordinal form, used for position in a sequence or for dates: "her thirtieth birthday," "the thirtieth of June." Note the spelling change: the final y of thirty becomes ie before -th.
Should you write thirty or 30 in formal writing?
It depends on the style guide. Some guides spell out numbers up to ninety-nine, so thirty would be written as a word, while others use figures for anything above nine, giving 30. Whichever convention you follow, apply it consistently, and always spell out a number that begins a sentence.
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