Wait, so "en" words are masculine and "ett" words are feminine? Or the other way around? Because that's what it's like in Slovak - for example "žena" (woman, wife) is feminine as well as "káva" (coffee), and you'd say "Miluje svoju ženu" and "Miluje svoju kávu" (He loves his wife, he loves his coffee). Is this principle the same in Swedish? Is "ett kaffe" a feminine noun?
Also, Slovak language (and I'd guess Polish and Russian too, though I'm not sure) has the third neutral gender, e.g. "mesto" (city) is neutral.
Yes - but only if the boy is drinking someone else's tea. Why? Because of reflexive possessive pronouns! :D
"The boy drinks his tea" is ambiguous. Is he drinking his own tea, or some other male person's tea?
Swedish doesn't have this ambiguity. The sentence can be translated to either "Pojken dricker sitt te" or "Pojken dricker hans te" depending on whose tea he's drinking.
Unfortunately even many native speakers make the mistake of writing hans/hennes when they mean sitt (or sin). And when there are multiple subjects in a sentence it can actually get tricky. But that also means you probably shouldn't worry too much about it while taking the first steps learning the language.
"Pojken dricker hans te" would mean the boy is drinking another boy's tea.
"Pojken dricker hennes te" when he is drinking a girl's tea.
"Pojken dricker deras te" if the tea he is drinking belongs to more than one person (but not to the speaker)
"Pojken dricker sitt te" means the tea belongs to the boy.
"Pojken dricker sina teer" if the teas belong to the boy and he's drinking more than one.
Swedish doesn't have a continuous tense, so there's no difference between "is drinking" and "drinks" - they're both dricker. You can translate to either one throughout the course, and if you ever need to distinguish between them in a real-life situation, you can derive it contextually.
Swedish folks might also be interested to know that in english a boy could eat his tea too as well as drink it, tea being a word used in some parts of the country to refer to the evening meal... you have to tell whether they mean the drink or the meal from the context.
There's also "afternoon tea", a late afternoon sit down undertaken especially by the upper classes, consisting of tea the drink accompanied by small sandwiches and/or scones(with cream and jam) and/or cakes. A bit like Germany's Kaffee und Kuchen.