pierwszego/pierwszy

Hello, please help me! I don't really understand the declension of the adjective in this sentence:
Jem dzisiaj dopiero pierwszego hamburger.

Can somebody explain me why is this pierwszego, not pierwszy? I know hamburger is a masculine noun, and it's in ACC with its adjective, but I thought that adjectives get -ego ending only if the noun is a masc. living thing.

Thanks a lot in advance...!

Jem dzisiaj dopiero pierwszy hamburger
pierwszy hamburger - accusative

jem dzisiaj pierwszego hamburgera is common, but wrong. it can only be used with a negation.
jem dzisiaj pierwszy hamburger is a little awkward, but technically correct.

what was wrong with the sentence you've given, is that you swapped the ending over between the two versions. Either dative or accusative, but in both words.

if you are looking for an explanation how this got established, then simply this is the ending that got inherited since times immemorial.

jem kogo? co? hamburger. który? pierwszy

nie jem kogo? czego? hamburgera. którego? pierwszego

Aha, my first instinct was to use the hamburgera option above but you are right to mention that it is used with negation. It just looks right to me but, then again, I'm not Polish and struggle with some grammatical aspects. I just know from sound some of the time.

With verbs such as jeść, pić and some other verbs one can use genitive instead of accusative - so called partitive genetive. However the senctence provided you must use accusative because you have one hamburger not a part of it.

Some examples of patitive gentive versus accusative:

Poproszę mleka (genitive) in this case we are not precise about the amount of it
versus
Poproszę mleko (accusative) in this case a carton/bottle of milk

Poproszę chleba (genitive) some bread

Poproszę jeden chleb (accusative) a loaf of bread

Generally genitive is more often used with uncountable nouns.

Genitive is also used with a negation, as said before.

Poproszę jeden chleb, aha, so that is why Poles say 'a bread'. I always say 'bochenek chleba, proszę'.

Analysing the phrase proszę bochenek chleba you get:

proszę co? (accusative) bochenek
bochenek czego? (genitive) chleba - loaf of bread

As you can see there is no adjective here only two nouns: bochenek and chleb, in Nominative case here so you can find the forms in a dictionary.

jeden chleb versus bochenek chleba

jeden chleb - a bread; jeden - a qualifier (adjectival numeral);
an example of so called agreement or concord in Polish związek zgody, adjective-noun agreement.

bochenek chleba - a loaf of bread; two nouns; an example of so called case government in Polish związek rządu.

Good analysis, Adam! Thankfully, I'm beyond that stage but the higher-level grammar is killer.

A Grammar of Contemporary Polish by Oscar E Swan - Excellent book for you to read:

http: //polish.slavic.pitt.edu/grammar.pdf

Mind the space in the address! (I've put it just to circumvent the admin restriction)

THAT.... is NOT "an excellent book" in any shape or form unless you have a wobbly table!
Roger's Profanisaurus is an excellent book!

.whsmith.co.uk/CatalogAndSearch/ProductDetails.aspx?productId=97819063 72323&shop=10004&type=Froogle

Thank you very much for answering!