Numeri ordinali (ordinal numbers) indicate, as the name suggests, order, succession, or classification. These numbers are regular adjectives, and therefore change gender and pluralize depending on the noun to which they refer. The following list shows the ordinal numbers in their masculine singular form:

primo – first

secondo – second

terzo – third

quarto – fourth

quinto – fifth

sesto – sixth

settimo – seventh

ottavo – eighth

nono – ninth

decimo – tenth

From ten onwards the ordinal numbers are constructed by adding the suffix ‘-esimo’ to the root of the cardinal numbers. For cardinal numbers see the following article: Numeri Cardinali 

For example:

undicesimo – eleventh

dodicesimo – twelfth

tredicesimo – thirteenth

diciottesimo – eighteenth

ventesimo – twentieth

trentesimo – thirtieth

cinquantesimo – fiftieth

and so on up to:

centesimo – one hundredth

millesimo – one thousanth

milionesimo – one millionth

ennesimo – nth

Here are some everyday example of the use of ordinal numbers:

‘Oggi è il primo giorno di primavera’ (today is the first day of spring), in which primo refers to giorno, so it is masculine singular.

‘Questa è la terza primavera di fila che veniamo qua in vacanza’ (this is the third spring in a row that we’ve come here on holiday), in which terza refers to primavera, so it is feminine singular.

‘Domani è l’ottantanovesimo compleanno del padre di Francesco’ (tomorrow is Francesco’s father’s eighty-ninth birthday), in which ottantanovesimo  refers to compleanno, so it is masculine singular.

‘È una tradizione che risale al dodicesimo secolo’ (it’s a tradition that goes back to the twelfth century), in which dodicesimo refers to secolo, so it is masculine singular.

‘Gli Americani sono stati i primi ad andare sulla Luna’ (the Americans were the first to go to the moon), in which primi refers to Americani, so it is masculine plural.

‘Le prime tre sere lo spettacolo era tutto esaurito’ (the first three evenings the show was completely sold out), in which prime refers to sere, so it is feminine plural.

Ordinal numbers are written numerically in the following way: for the masculine form; 1o, 2o, 3o, etc. for the feminine form; 1a, 2a, 3a, etc. The plural forms, e.g. 1i, 2i or 3e 4e, are rarely used. N.B. These numbers are usually written with a small o or a to the upper right of the numeral but unfortunately I can’t reproduce this with my keyboard.

 

In certain situations Roman numerals are used, e.g. Enrico VIII (Henry the Eighth), Papa Benedetto XVI (Pope Benedict the Sixteenth).

Ecco finito il secondo articolo che tratta dei numeri italiani, alla prossima.