"What is the boy drinking?"
Translation:Co pije chłopiec?
A) Polish language does not have articles, you can when needed use "this"=ten/ta/to, but they are not necessary.
B) Polish "To" has two meanings, functions, both unfortunately teanslate to this/that.
To jest = this is - does not change depending on gender
Ten chłopiec/ta dziewczynka/to dziecko= this boy/this girl/this child - changes depending on gender
Jacek to (jest) chłopiec -Jacek is a boy TO is part of the set expression, never changes
C) English has continous tense that has "is drinking" as version of "to drink" , there is no "be= jest" in Co pije chłopiec, only is drinking/drinks=pije