OK, I translated this incorrectly as "I don't have a suit." I understand now that "completo" is the word for suit. However, the translation I was given was "I don't have a habit." In English, "a habit" refers to a garment worn by a monk or nun. "I don't have a costume" seems a better translation. Shouldn't that be the translation given in the lesson? Doesn't it better convey the meaning of "un costume" in a more general sense?
To further the discussion then the translation "I do not have a habit", in English simply would invite the question: "A good habit or a bad one?" - obviously nothing to do with clothing but manners and attitude. So, costume has to be translated either by "a bathing suit" or simply "a suit" the latter meaning either: trousers and matching jacket or skirt and matching jacket.
my point was not related to habit/suit, but to the sentence structure. duo allows "I have no habit", but doesn't allow "I have no suit", it requires "I do not have a suit" instead. it seemed that the same structure was allowed for habit but not for suit and it didn't make sense to me (still doesn't)
5 years later and this still has not been corrected. A habit is only warn by the clergy. I know we are learning Italian but still. Costume in English is a suit or at worth a costume, although in this case we have to be careful because costume also means clothing to disguise oneself such as for Mardi-Gras. Now, if Costume means a bathing suit, which I am quite prepared to accept since in French we say: "un costume de bain" then at least have the courtesy to show us such a picture first to avoid confusion.
Reading the thread I see that the translation of the Italian "costume" is variable and the "best" translation is debatable. My issue with this, however, is not the precise translation, but the inconsistency of usage by Duo. Sometime (i.e., on some cards) "suit" is accepted. Here is is not. Google translate shows that the english "suit" is sometimes translated as Italian "costume". Duo, if it accepts "suit" in some cases, needs to accept it in all cases or else it needs to make a clear distinction between cases and teach us the difference. Arbitrarily accepting it sometimes and rejecting it other times is the worst possible behavior in a learning environment.