Questions & Answers about Mam cukierki dla dzieci.
Why is it cukierki instead of just cukierek?
The verb mieć (to have) always takes the accusative case for its object. Since we are talking about plural "sweets", we need the plural accusative form. For masculine inanimate nouns like cukierek, the plural accusative is the same as the basic plural (nominative) form, making it cukierki.
What case follows the word dla?
The preposition dla (for) always forces the noun that follows it to be in the genitive case. This is a strict rule in Polish, so whenever you have something "for" someone, remember to use the genitive!
Wait, isn't dzieci just the basic plural word for "children"? Why isn't it changing for the genitive case here?
Good catch! You are right that dzieci is the basic plural (nominative) for dziecko (child). However, the word for "child" is highly irregular in Polish. Its genitive plural form just happens to be exactly the same as its nominative plural form: dzieci.
Why can't I say dla dzieciom?
English speakers often confuse having something "for" someone with giving something "to" someone. If you give something to the children, you use the dative case (dzieciom) without a preposition. But because we used the word dla (for) here, we are locked into using the genitive case (dzieci).