So pa sig must always follow har when the subject is wearing something ?
If you leave it out, you can't be sure if they're wearing it or just 'have' it, like in own it.
Nah, this is a false friend word, as "en kostym" means "a suit", while "costume" on the other hand translates more to "dräkt" and could be quite much any kind of thematic clothing such as a traditional costume or a a costume for a costume party.
I don't think it's that odd: "costume" can mean "suit" in French, where I think the word originated. And I believe that both Swedish and Russian have borrowed from French a good deal.
I may have missed 'sig' somewhere. What does this mean? Is it the plural for 'sitt'? I thought it was 'sina'?
No, sig is the third person reflexive pronoun. It means himself/herself/itself/themselves.
No, that would be "han har på sig sin kostym" "De har på sig sina kostymer" would be "They wear their suits"
What about "They have on the suits." I feel that this should be right.
That unfortunately fails in the department of correct grammar. "They have the suits on" would be correct in English, and you can also say "De har kostymerna på sig" In Swedish too.
Would it be wrong to say that this means "They wear their suits" since something like "Hon har på sig kostymen" would more than likely mean "She wears her suit". It was marked wrong but it feels to me like it should be right
I've added that, it's possible here. The general idea is that it's reasonable to think that a Swedish determinate can mean an English possessive in cases where the first interpretation would be that you are talking about something that belongs to the subject – it's about something that you are expected to have. For instance, Vi borstar tänderna We probably brush our teeth, not just some other teeth. Vi köper äpplena We're not likely to buy apples that are already our own, so no way. Vi läser tidningarna There's no good reason to assume we're reading our own newspapers. It could happen in real life (although rarely) that tidningarna would be our newspapers but shouldn't happen in this course since it is unlikely.
How do I tell the difference between "de" and "dem" when someone is speaking? As far as I know, they're pronounced the same.
You can't, they sound the same. You can only know from grammar. Many Swedes struggle with this, but you're lucky that you already know English – just use de for they and dem for them and you'll be fine most of the time.
So if 'en kostym' is 'a suit' and 'kostymerna' is 'the suits', how would we say 'suits'?
I wrote "they are wearing the suits" and got it wrong. Am I wrong or is it a glitch?
Yep same here. Wrote "they are wearing the suits" got it wrong. I think its a glitch
Am I correct in thinking that "They wear the suits," takes on an air of authority in regard to the subjects in question? For example, I read it as one might say in English, "He [or she] wears the pants in this organization." That is, "They're in charge. They're the bosses. They wear the suits."
I do understand that--grammatically--this could mean, "They wear [these particular] suits," as indicated by the speaker... but I'm trying to understand how this sentence would likely come up in conversation.
Conversationally, how would this sentence typically be interpreted by a reader?