Numerals

A complete list of the Polish numbers (Cardinal and Ordinal), you find at this external page.

Cardinal numbers:
They are declined as adjectives.

One (jeden, jedna, jedno)

	Singular: Masculine	Singular: Feminine	Singular: Neuter	Plural: Non-men	Plural: Men
Nominative	jeden	jedna	jedno	jedne	jedni
Accusative	jeden (for things) jednego (for creatures)	jedną	jedno	jedne	jednych
Genitive	jednego	jednej	jednego	jednych	jednych
Locative	jednym	jednej	jednym	jednych	jednych
Instrumental	jednym	jedną	jednym	jednymi	jednymi
Dative	jednemu	jednej	jednemu	jednym	jednym

Actually there is no accusative form for Masculine creatures (men, animals, etc.), so the genitive is used instead.

Two (dwa, dwie, dwa):
For persons of mixed gender, children and young animals, one uses dwoje. The same applies to objects that don't have a singular form.

	Masculine (men)	Masculine (non men) and neuter	Feminine	Mixed
Nominative	dwaj	dwa	dwie	dwoje
Accusative	dwóch	dwa	dwie	dwoje
Genitive	dwóch	dwóch	dwóch	dwojga
Locative	dwóch	dwóch	dwóch	dwojgu
Instrumental	dwoma	dwoma	dwiema	dwojgiem
Dative	dwom	dwom	dwom	dwojgu

Three (trzy) and four (cztery):
For persons of mixed gender, children and young animals, one uses troje (czworo). The same applies to objects that don't have a singular form.

	3: men	3: other	3: mixed	4: men	4: other	4:mixed
Nominative	trzej (trzech)	trzy	troje	czterej (czterech)	cztery	czworo
Accusative	trzech	trzy	troje	czterech	cztery	czworo
Genitive	trzech	trzech	trojga	czterech	czterech	czworga
Locative	trzech	trzech	trojgu	czterech	czterech	czworgu
Instrumental	trzema	trzema	trojgiem	czterema	czterema	czworgiem
Dative	trzem	trzem	trojgu	czterem	czterem	czworgu

There are two different forms for the men nominative case: The 1st requires the verb being in plural. While the 2nd version (which usually is used in colloquial Polish) demands a verb in singular but the noun has to be in the genitive case.

Five (pięć) and onwards:
These numbers are, in the nominative and accusative case) only declined when they refer to men. There is only one declination for these numbers. In Polish all numbers from 5 onwards are treated as quantities. This means that a number in the nominative, accusative or genitive case always refers to a noun in the genitive case.
The instrumental case has an alternative ending for numbers 5-90. This replaces the u with oma:
pięcioma, cześcioma, dziewięcioma, etc...
Numbers consisting of up to 3 elements, decline each unit. Exception: jeden is never declined when not alone. Numbers of more than 3 elements decline usually only the last two units. But there is also the possibility to decline all elements.
 

5 pięciu	10 dziesięciu	15 piętnastu
6 cześciu	11 jedenastu	16 szesnastu
7 siedmiu	12 dwunastu	17 siedemnastu
8 ośmiu	13 trzynastu	18 osiemnastu
9 dziewięciu	14 czternastu	19 dziewiętnastu

20 dwudziestu	80 osiemdziesięciu	500 pięciuset
30 trzydziestu	90 dziewięćdziesięciu	600 sześciuset
40 czterdziestu	100 stu	700 siedmiuset
50 pięćdziesięciu	200 dwustu	800 ośmiuset
60 sześćdziesięciu	300 trzystu	900 dziewięciuset
70 siedemdziesięciu	400 czterystu

Thousand (tysiąc) and million (milion):
They are declined as nouns and are always followed by a noun in the genitive case. Nevertheless they only take a singular verb.
 

	singular	plural	singular	plural
Nominative	tysiąc	tysiące	milion	miliony
Accusative	tysiąc	tysiące	milion	miliony
Genitive	tysiąca	tysiący	milion	milionów
Locative	tysiącu	tysiącach	milionie	milionach
Instrumental	tysiącem	tysiącami	milionem	milionami
Dative	tysiącowi	tysiącom	milionowi	milionom

Ordinal numbers:
These are declined as adjectives.

Indefinite numbers:
Such numbers in the nominative, accusative and genitive case the following noun has to be in the genitive case. The verb follows in singular. There are two possible endings for the instrumental case.

	11-19	20-90	100-900	a few	several	many	so many	how many
Nom / Acc (men)	kilkunastu	kilkudziesięciu	kilkuset	paru	kilku	wielu	tylu	ilu
Nom / Acc (others)	kilkanaście	kilkadziesiąt	kilkaset	parę	kilka	wiele	tyle	ile
Gen/Loc/Dat	kilkunastu	kilkudziesięciu	kilkuset	paru	kilku	wielu	tylu	ilu
Ins	kilkunastu kilkunastoma	kilkudziesięciu kilkudziesięcioma	kilkuset	paru paroma	kilku kilkoma	wielu wieloma	tylu tyloma	ilu iloma

Fractions and decimal numbers:
They consist of a cardinal number followed by an ordinal number which is declined as an adjective. These expressions are feminine. Any noun to which this number is referred to stands in the genitive case.
Important: In the Polish language one uses the comma as the decimal point.
e.g.:
half = pół (this is not declineable) or połowa (what is a noun)
third = jedna trzecia
two thirds = dwie trzecie
0.1 0,1 = jedna dziesiąta
0.5 0,5 = pięć dziesiątych

Age:
To express how old some one is you have to say that this person got ... years.
The plural of rok (year) is lata (summers).
Mam dwadziestu pięciu laty. (I'm 25 years old)

Dates and times:
The day, the month and year stand in the genitive case. While in the year only the last two digits are declined.

The clock time is expressed with the ordinal number plus the words godzina (hour) and minuta (minute). Both are female.
You would say:
"at what hour?"
"it's the 8th hour and 20 minutes"
Godzina and minuta are usually omitted.