I'd like to know precisely how the Chinese language syntax conveys in the fewest possible number of words the meanings that English syntax expresses with simple copulative sentences.
For example, (1) can be used to respond to someone saying Jenny is behaving outrageously; it means that such behavior is ordinary behavior for her (i.e. Jenny is exhibiting the traits she always has had). (2) means exactly the opposite: she's now behaving out of the ordinary.
(1) Jenny is Jenny
(2) She's not being herself today
Sometimes in English we also identify participants of the conversation or its surroundings. For example, if we are talking with a friend about a couple of artists that he knows and, while we're talking, we happen to see people just like them in the street, we can point to them and utter (3). Moreover, if four kids are staging a play and deciding who plays who, one of them can utter (4).
(3) Are they them?
(4) He's me and she's you
Do these structures have equivalents in Chinese? I'm not interested in the translations per se; what I want to know is what syntactic structure is used to express sentences like (1)-(4).