"They cannot stand it anymore!"
Translation:Elas não aguentam mais!
Then it would be "eles não podeM aguentar mais" or "eles não podeM mais aguentar". When you have to verbs together, you conjugate just the first one. The other you use as infinitive (aguentar) (plus, you can add isso at the end once we have "it" at the end of the english sentence)
Maybe you could add it as a correct answer? :-) I get marked wrong every time I say "Não aguentam mais," although I've reported it....
(Even better, it keeps telling me that I specifically need "Elas." Not sure how I'm supposed to know that the people who can't stand it are female :-))