"They belong to you!"
Translation:הם שייכים לכם!
There's nothing wrong with what you wrote. You are saying, "They belong to you" where "you" is singular. Their answer was a "you" that was plural. As we would say in the southern part of the U.S., "They belong to y'all." Or in some areas we would say, "They belong to you guys." It's too bad that English lost the distinction between singular and plural for "you." Singular used to be "thee" in the accusative or dative and "thou" in the nominative. You can still see this in the KJV Bible and others and some prayer books and hymns.
I don't think it is, I'm just learning too, but in Google translate and in REVERSO, both translate, they belong to you as: הם שייכים לך or הן שייכות לך .
"Translation:הם שייכים לכם!"
Correct answer on screen given as "הם שייכים לכן!"
לכן vs לכם
Both ok it seems?
Yes, both are fine. The one ending on mem means the "you" being addressed is more than one person (either all male or a mixed group) whereas the one ending in nun is an all-female group.
The correct answer given to me was הן שייכות לכן . How different do they translate?