fifty

• 数词，表示五十个事物、人或计数单位；十的倍数；也可作名词、限定词或代词使用。

The cardinal numeral representing the quantity of fifty units; the fiftieth positive integer following forty-nine; a composite number (2×5²); a round multiple of ten commonly used in counting, measurement, percentages, and milestone celebrations. Also functions as a noun (denoting the symbol, quantity, or group of fifty), adjective/determiner (modifying nouns to indicate quantity), and pronoun (standing in for a plural noun phrase).

1. Cardinal numeral: the number 50A1formal

   Used to denote a quantity of fifty persons or things; the fiftieth positive integer in the sequence of natural numbers; a composite number (2×5²); represents a fiftyfold quantity in counting, mathematics, and everyday usage.

   基数词：数字50

   • There are fifty states in the United States.
   • She scored fifty points in the competition.
   • Fifty plus fifty equals one hundred.
   • The speed limit is fifty kilometers per hour.
   • He completed fifty laps during training.

2. Noun: the number, symbol, or group of fiftyA2formal

   A noun referring to the cardinal number fifty; the numeral symbol 50 or L; a set, collection, or group consisting of fifty items; a playing card displaying fifty (in extended decks); a team or ensemble of fifty members; in currency, a fifty-unit banknote.

   名词：数字、符号或五十的集合

   • The number fifty marks a golden anniversary milestone.
   • Circle the fifties in this financial summary.
   • The orchestra includes a fifty of musicians.
   • In some card variants, the fifty is a special scoring card.
   • The budget report lists a fifty of contracted suppliers.

3. Adjective/Determiner: amounting to fiftyA1formal

   Used attributively before a noun to indicate that the quantity or number of the noun is fifty; modifies plural countable nouns to specify exact quantity.

   数量词/形容词：五十的

   • They booked a fifty-week research project.
   • We need fifty additional passes for the event.
   • The protocol requires fifty milliliters of the solution.
   • She has fifty years of experience in journalism.
   • Fifty international partners supported the initiative.

4. Pronoun: fifty people or things (plural)B1formal

   Used as a pronoun to refer to fifty previously mentioned or understood persons or things; takes plural verb agreement.

   代词：五十个人或事物

   • Five hundred applied, but only fifty were selected for the program.
   • I invited three hundred guests; fifty confirmed their attendance.
   • How many seats should we reserve? — Fifty will be ideal.
   • Several firms submitted tenders, but fifty advanced to the final evaluation.
   • Of the proposals reviewed, fifty were approved for funding.