Say that a Flowerew (a wolf which turns into a human on the full moon) is pretending to be human during their human phase. Or that a kitsune who has been a fox for their life so far is trying their hand at faking humanity. Or perhaps an alien has beamed down to save Earth from impending disaster without breaking the Prime Directive.
I want to give some way for them to be identifiable based on failing to pick up on social cues or not understanding social norms. Not things which are necessarily massively obvious; just social norms which it would be difficult to grasp for someone not growing up in today's human society.
What's the most likely social cue/norm for them to struggle with the most?
EDIT: Yeah, this question was too broad, so instead, I ask: what social norms would a wild animal who had been metamorphosised into a human struggle with the most? They are intelligent in that they can speak and have a wide vocabulary, but do not know what to say or how to act beyond what they imitate from people they observe.
As for the target society, let's say Western society, e.g. the USA and any place with similar social rules.
EDIT TO EDIT: I'll make it even more precise: how would a (wild) fox that has been transformed into a human struggle to follow social norms/rules in the USA?