thirtieth

• 序数词，用来表示某事物在序列中排在第30位。

An ordinal number used to describe the position of something in a sequence that is number 30 in order.

1. Ordinal numberA2formal

   Coming immediately after the twenty-ninth in a sequence or order.

   第三十

   • She celebrated her thirtieth birthday last week.
   • The thirtieth chapter of the book is the most exciting.
   • He finished in thirtieth place in the marathon.

• 表示序列中第30个位置或排名的名词；也可指三十分之一。

A noun referring to the position or rank that is number 30 in a countable sequence of items.

1. Position 30 in a seriesA2formal

   The item or person that is number 30 in a sequence or order.

   第三十个

   • He was the thirtieth person to arrive at the party.
   • The thirtieth chapter of the book is the most exciting.
   • She finished in thirtieth place in the marathon.

• 基数词，表示三十个事物、人或计数单位；是十的倍数；也可作名词、限定词或代词使用。

The cardinal numeral representing the quantity of thirty units; the thirtieth positive integer following twenty-nine; a composite number (2×3×5); a multiple of ten commonly used in counting, measurement, and timekeeping. Also functions as a noun (denoting the symbol, quantity, or group of thirty), adjective/determiner (modifying nouns to indicate quantity), and pronoun (standing in for a plural noun phrase).

1. Cardinal numeral: the number 30A1formal

   Used to denote a quantity of thirty persons or things; the thirtieth positive integer in the sequence of natural numbers; a composite number (2×3×5); represents a thirtyfold quantity in counting, mathematics, and everyday usage.

   基数词：数字30

   • There are thirty days in April.
   • She scored thirty points in the volleyball match.
   • Thirty plus thirty equals sixty.
   • The briefing starts at thirty past the hour.
   • He completed thirty laps around the track.

2. Noun: the number, symbol, or group of thirtyA2formal

   A noun referring to the cardinal number thirty; the numeral symbol 30 or XXX; a set, collection, or group consisting of thirty items; a playing card displaying thirty (in extended decks); a team or ensemble of thirty members; in currency, a thirty-unit note or coin.

   名词：三十这个数、符号或一组三十

   • The number thirty marks a significant anniversary milestone.
   • Circle the thirties in this statistical table.
   • The choir consists of a thirty of vocalists.
   • In some card variants, the thirty holds special scoring value.
   • The historical record mentions a thirty of appointed delegates.

3. Adjective/Determiner: amounting to thirtyA1formal

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

   数量为三十的

   • They booked a thirty-day expedition to the Arctic.
   • We need thirty additional chairs for the conference hall.
   • The chemical formula requires thirty milliliters of the solvent.
   • She has thirty years of experience in clinical research.
   • Thirty international organizations endorsed the sustainability charter.

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

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

   代词：三十个人或事物

   • Two hundred applied, but only thirty were selected for the fellowship.
   • I invited one hundred guests; thirty confirmed their attendance.
   • How many seats should we reserve? — Thirty will be ideal.
   • Several startups pitched, but thirty advanced to the accelerator program.
   • Of the manuscripts evaluated, thirty were accepted for publication.