"He is a boy."
Translation:On jest chłopcem.
What is the difference between "On jest chłopcem" and "On jest chłopakiem"?
cases. chłopca is genitive=accusative, chłopcem is instrumental.
We use instrumental case of noun after "jest"., when meaning "is someone/something"
The sentence you ask about : On jest chłopca is correct Polish sentence meaning He(It) is the boy's. It belongs to the boy.- genitive among other things is used to indicate posestion
Ive been learning yhat boy means "chlopiec" so when i type it, it days its wrong so i would like to know why they make us learn a certain word and then go back and trick us with a word we havent learned before.
a/the don't exist in Polish, so they're irrelevant.
"jestem" means "I am" and "jest" means "he/she/it is". Because of that, the pronouns are generally redundant, as the form of the verb already makes it clear what person is that.
Yes. On Duolingo, almost all sentences starting with He/She/They use the pronoun explicitly, but in fact that's not that common. We are looking at standalone sentences without any context here, but in real life you do have context.
If you say "This is Adam. He is a boy.", it's enough to say "To jest Adam. Jest chłopcem." because you just stated the subject a moment earlier. In fact it's not very natural to use these pronoun subjects if it's already clear who the subject is.
Firstly, "chłopak" turns into "chłopakiem", and "chłopiec" turns into "chłopcem". The first options are Nominative, the second ones are Instrumental.
Nominative is mostly used for the subject of the sentence. Instrumental is used in sentences like here: "He is Y" (where Y is a noun phrase).
More info here: https://www.duolingo.com/comment/16373167