Let's learn the words first, second (usually called ordinals or ordinal numbers). They behave as adjectives in Croatian. Their forms are:
1 prvi first|
2 drugi second
3 treći third
4 četvrti fourth
5 peti fifth|
6 šesti sixth
7 sedmi seventh
8 osmi eighth
Of course, the adjective drugi also means other.
For higher numbers, you should just add -i to them, if they consist of only one word:
17 sedamnaest → sedamnaesti
40 četrdeset → četrdeseti
If a number consists of more than one word, just change the last word into the ordinal form; if a number is in a compact form (without the i) just change the last part:
31 trideset i jedan →
trideset i prvi
31 tridesetjedan → tridesetprvi
One thing the ordinal numbers are used for in Croatian is for dates. In Croatian, e.g. the year 1932 is understood as the '1932nd year' or just the 'thirty-second' year.
In Croatian, when you want to say that something happened (or happens, or will happen) on a given day, month or year (expressed as a date), you should put the date in the genitive case.
Bilo je to trideset i druge (godine). lit. 'It was in the 32nd (year).' = It was in thirty-two.
Also, days in a month are referred to as the first, the second (the same is in English, but in the genitive case), and Croatian treats months in the same way: the first month (in a year), the second... ®. Normally people would just say:
Rođen sam petog osmog. 'I am born on the fifth of the eighth.' = I am born on the fifth of August.
Of course, both petog and osmog are genitives of ordinal adjectives peti and osmi (in masc.), since it's just short for petog dana and osmog mjeseca – and both dan and mjesec are masculine.
In the Croatian writing of numbers, ordinal numbers are abbreviated to just number + a period, so it's usually written:
Rođen sam 5. 8.
This is the word used to describe a specific date:
If you want to talk about a date related to an event, you add the event in the genitive case:
datum rođenja date of birth
To say that something happened/happens sometime in a given month, use u¨ + DL:
Rođen sam u osmom mjesecu. I'm born in August.
The word mjesec is sometimes abbreviated as mj.; colloquially, even mjesec month can be left out: ®
Idemo na more u sedmom. We're going to seaside in July. ®
There are also names of months in Croatian, but they are mostly used in formal writing, books, etc.; they are normally not capitalized (similar to days of week): ®
iječanj (s iječnj-) January
2 veljača February
3 ožujak (ožujk-) March
4 travanj (travnj-) April
5 svibanj (svibnj-) May
6 lipanj (lipnj-) June
7 srpanj (srpnj-) July
8 kolovoz August
9 rujan (rujn-) September
10 listopad October
11 studeni (adj.) November
12 prosinac (prosinc-) December
Of course, they must be also put to genitive when used in the above meaning (when something happened/happens):
Rođen sam petog kolovoza. I am born on the fifth of August. (formal)
Rođen sam u kolovozu. I am born in August. (formal)
When the date is the subject, the first word should be in nominative, but the rest of the date must stay in the genitive case, since you are actually talking about the Xth day of some month of some year and all those of's correspond to the Croatian genitive case:
Peti kolovoza je bio vruć. The fifth of August was hot.
Again, the expression above is actually about peti dan the fifth day – therefore, the past form is in masculine.
The adjective prvi is often used in spatial arrangements, when English usually uses front instead:
prvi red front row (lit. 'first row')
prva crta front line (lit. 'first line')
Another very frequent use of ordinal numbers is talking about levels in a building. Croatian uses the same scheme as British English – the floor above the ground level is the first floor:
|drugi kat||the second floor ®|
|prvi kat||the first floor|
|prizemlje||the ground floor|
The word kat ® means only storey, level in a bulding, not surface you walk on (the other meaning of English floor). For surfaces, the word pod is used.
If you use only na katu (or direction na kat), the first floor is assumed:
Kupaonica je na katu. The bathroom is on the first floor.
For prizemlje and podrum, you should use the preposition u¨; for all levels above, the preposition na¨ is used:
Kutija je u podrumu. The box is in the basement.
Ured je na drugom katu. The office is on the second floor. ®
Igračke su na tavanu. The toys are in the attic.
The opposites of prvi first are:
(The adjective posljednji is a bit more formal.) An example for zadnji:
Ana živi na zadnjem katu. Ana lives on the top floor. (lit. 'last floor')
While in English, you can just use first as an adverb (e.g. first, you mix flour with eggs...), in Croatian you must use its 'adverbial' form, that is, neuter singular prvo. Instead of posljednje, the form na kraju is used in meaning finally.
® In Serbia, ordinal numbers are usually not used for months (except when reading dates written as numbers); specific names – different than Croatian – are used even in the colloquial speech:
1 januar January|
2 februar February
3 mart March
4 april April
5 maj May
6 jun / juni June
7 jul / juli July|
8 avgust August
9 septembar (septembr-) September
10 oktobar (oktobr-) October
11 novembar (novembr-) November
12 decembar (decembr-) December
As you can see, these names are similar to the English names. Those names also prevail in Bosnia and Montenegro. Ordinal numbers for months are infrequent in Bosnia and sometimes used in Montenegro.
The following words are less often used in Serbia and Bosnia (words more common there are given after arrows):
kat → sprat
ured → kancelarija