Ordinal numbers & dates

Rules

• Rule 1: The first three are special

  Learn these by heart: first (1st), second (2nd), third (3rd). In the short form we add the last two letters of the word: first → 1st, second → 2nd, third → 3rd.

  Pattern: 1 → first (1st) · 2 → second (2nd) · 3 → third (3rd)

  Example: Monday is the first day of our school week.

  Example: Our class is on the second floor.

• Rule 2: Most others add -th

  From 4 on, we add -th: fourth, sixth, tenth. Some spellings change: fifth, eighth, ninth, twelfth. Numbers ending in -ty change y → ie: twentieth.

  Pattern: number + -th · fifth, eighth, ninth, twelfth, twentieth

  Example: Today is my ninth birthday!

  Example: December is the twelfth month.

• Rule 3: 21, 22, 23… look at the last digit!

  In bigger numbers only the last word becomes an ordinal: twenty-first (21st), twenty-second (22nd), thirty-first (31st). But 11th, 12th, 13th always take -th.

  Pattern: 21st · 22nd · 23rd · 24th — but 11th, 12th, 13th

  Example: The fair is on June 21st.

  Example: My test is on May 12th.

• Rule 4: American dates

  Americans write the month first: May 3rd or May 3, and always say it with an ordinal: “May third”. The short form is month/day: 5/3 = May 3. Use on with a date and in with a month alone: on May 3rd, in May.

  Pattern: month + day: May 3rd · on + date · in + month

  Example: School ends on June 14th.

  Example: In the U.S., 7/4 is July 4th.

Common mistakes

• My birthday is on May three. → My birthday is on May third.

  We say dates with ordinals.

• The party is on the 12nd. → The party is on the 12th.

  11, 12 and 13 always take -th.

• Today is my nineth day here. → Today is my ninth day here.

  nine → ninth: the e drops.