"You laugh and cry."
Translation:Te nauratte ja itkette.
"They" is always in third person, so neither plural nor singular "they" would be applicable here. Also, this course avoids and doesn't accept the usage of the singular "they" in cases where it would create ambiguity about numerus (which would be most of the time). When it comes to "you", both "sinä" and "te" are supposed to be acceptable Finnish translations unless the linguistic context indicates otherwise. When that isn't the case, it's advisable to click the report button and select "my answer should be accepted" because the people who can actually do something about it are probably not checking every sentence discussion thread.