As far as I've been able to figure, aquí means right here, and acá means sort of around here, not as precise as aquí.
it's the same thing, here in argentina you are more likely to hear people use aca
Same here - so many of these very basic errors/oversights on here. Hopefully they fix them soon
I think you two just picked the wrong contraction! I personally think it is simpler not to have any contractions and I have never been "wronged" for not using one. But this iteration Duo is throwing around - and also accepting - stuff like don't. My advice is only use a contraction you've seen Duo use! Tough luck...
Ha ha! You could say the names of other students who are missing from class.