"A boy is drinking water."
Translation:En pojke dricker vatten.
When we use " är " and when we don't . for ex. Why it is ( En pojcke dricker vatten ) not ( En pojcke är dricker vatten )
In English, they have two constructions is drinking and drinks, but in Swedish we've only got one, dricker, for the present. So both is drinking and drinks are always just dricker.
Pojke is an en-word. All Swedish words are either an en-word or an ett-word, and it's important to learn the grammatical gender by heart.
Kille is a little more colloquial. pojke is normally only used about children whereas kille can be either a child or a young man. Also, din kille can mean your boyfriend, whereas din pojke will only be interpreted as your son. But in very many cases, both work.