twenty-first
A1Neutral; used in all registers from formal to informal.
Definition
Meaning
The ordinal number corresponding to the cardinal number 21; the position or item in a sequence after the twentieth.
The day of a month; the celebration of a 21st birthday; designating something in the 21st position in a series.
Linguistics
Semantic Notes
Functions primarily as an adjective or noun. As a noun, it often refers specifically to a 21st birthday celebration.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Both use 'twenty-first' for the ordinal number and the birthday.
Connotations
In both cultures, 'the twenty-first' strongly connotes the age of legal majority (for activities like drinking in the UK, or drinking/voting in the US).
Frequency
Equally frequent. The noun form 'twenty-first birthday' is extremely common.
Vocabulary
Collocations
Grammar
Valency Patterns
the twenty-first of [Month]her twenty-first [birthday]in the twenty-first centuryon the twenty-firstVocabulary
Synonyms
Strong
Neutral
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “The key of the door (UK, traditional gift for 21st birthday)”
Usage
Context Usage
Business
Referring to fiscal quarters, deadlines, or report editions (e.g., 'the twenty-first quarterly report').
Academic
Referencing centuries, chronological order, or list positions (e.g., 'the twenty-first element in the series').
Everyday
Overwhelmingly used for dates and birthdays (e.g., 'See you on the twenty-first!').
Technical
Used in numbering sequences in software, engineering, or legal documents (e.g., 'Article Twenty-One').
Examples
By Part of Speech
adjective
British English
- Her twenty-first birthday party is next Saturday.
- We live in the twenty-first century.
- This is the twenty-first edition of the journal.
American English
- He just had his twenty-first birthday.
- The Twenty-first Amendment repealed prohibition.
- Please turn to the twenty-first chapter.
Examples
By CEFR Level
- My birthday is on the twenty-first of March.
- She is twenty-one years old.
- We're meeting for lunch on the twenty-first.
- He received a watch for his twenty-first.
- The conference has been rescheduled for the twenty-first.
- The twenty-first century has seen rapid technological change.
- The manuscript, dating from the twenty-first dynasty, is remarkably well-preserved.
- Her twenty-first attempt to quit smoking was finally successful.
Learning
Memory Aids
Mnemonic
Think: 'Twenty' + 'First'. It's the first number after twenty.
Conceptual Metaphor
A GATE/THRESHOLD (especially for the 21st birthday, marking the transition to full adulthood).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not translate as 'двадцать один' (21) when an ordinal is needed. Use 'двадцать первый'.
- In dates, English uses ordinal numbers ('the twenty-first'), while Russian typically uses cardinal numbers in the genitive ('двадцать первого').
Common Mistakes
- Writing '21th' instead of '21st'.
- Using cardinal 'twenty-one' where ordinal 'twenty-first' is required (e.g., '*I was born on twenty-one May').
Practice
Quiz
Which is the correct written form for the ordinal number?
FAQ
Frequently Asked Questions
Yes, ordinal numbers from twenty-first to ninety-ninth are hyphenated.
Yes, especially to mean '21st birthday' (e.g., 'We celebrated her twenty-first').
You say 'the twenty-first of June' (UK/commonwealth) or 'June twenty-first' (US).
Historically, it marked the age of legal majority and full adult rights in many countries, like the right to vote.