Complete Guide to Ordinal Numbers: Uses, Differences, and Exceptions

Importance of ordinal numbers

Ordinal numbers are relevant for our Concretely, Ordinal numbers are used to draw up placements and lists, for dates and centuries, birthdays or anniversaries.
Some examples can be:

“I found out only today that the 17th of March I’ll have a Math test”

(ho scoperto solo ora che il 17 marzo avrò una verifica di matematica)

“Lucy told me that she was the third of four children”

(Lucia mi ha detto che è la terza di quattro figli)

“Even though the athlete got injured, he managed to come second in the race”

(anche se l’atleta si è fatto male è riuscito ad arrivare secondo in gara)

"The husband had a look to the shopping list his wife made for him: he needed to buy milk first and then eggs"

(il marito ha dato un'occhiata alla lista della spesa fatta dalla moglie per lui: deve comprare il latte per primo e poi le uova)

Linguistic differences

It can be noticed that, differently from Italian, that Ordinal numbers are the same both for

1st first

2nd second

3rd third

4th fourth

5th fifth

6th sixth

7th seventh

8th eighth

9th ninth

10th tenth

11th eleventh

12th twelfth

13th thirteenth

14th fourteenth

15th fifteenth

16th sixteenth

17th seventeenth

18th eighteenth

19th nineteenth

20th twentieth

21st twenty-first

22nd twenty-second

23rd twenty-third

24th twenty-fourth

25th twenty-fifth

26th twenty-sixth

27th twenty-seventh

28th twenty-eighth

29th twenty-ninth

30th thirtieth

31st thirty-first

40th fortieth

50th fiftieth

60th sixtieth

70th seventieth

80th eightieth

90th ninetieth

100th one hundredth

1,000th one thousandth

1,000,000th one millionth

Formation of ordinal numbers

The process of creating an ordinal number is normally quite simple and regular, as the table shows, because it is only required to add -th at the end of a cardinal number but there are some exceptions that needs to be pointed out.

For example, the first three numbers (one, two, three) have their own forms which are These forms are used also in the For example 22nd should be written as twenty-second or 31st as thirty-first and 43rd as forty-third.

Exceptions in formation

As it can be seen, all the Ordinal numbers from twenty-first (21st) contains a Moreover, when we talk about tens which terminate as -ty like fifty (50) or eighty (80), -th is substituted by -ieth so 50th will be fiftieth and 80th eightieth.

In the end, numbers as 5, 9, 8, 12 have a different forms from the canonical ones because they are written as fifth, ninth, eighth and twelfth.