I think you may be confused by a very confusing feature of this language, the phrase "ann an." "An" means "the" in English, but for some baffling reason that the moderators tried heroically, but vainly, to explain to me, "ann an" means "in a," not as one would expect, in the. There is also a way to say "in the," but it seems to be so complex that the course never introduces it.
I can't see how old this comment is on my phone, so my reply might be incredibly late.
However 'taigh-beag' is 'a toilet', while an taigh-beag' is 'the toilet'. This seems to be shown correctly in the tips which only translates 'taigh-beag' as '(a) toilet'. But clearly this could have been different when you posted your comment.