a1) c'e` una luce is a contraction of: a2) ci e` una luce The particle /ci/ in this case has the meaning of one of: qui, la` (here, there) The word /cio`/ which has the meaning that you said is never changed. There is another word: cioe`, that derives from cio` and means /it means/, somebody uses cioe` as a meaningless filler in the conversation, which (in my view) is quite ugly to listen to. /ci/ has also other meanings, like: /to us/.

Hi my friend. I'm italian. "C'è" it means "There is". "Ciò" is like i'm saying "this/that". -C'è una luce nella stanza (There is a light in the room) -Ho visto ciò che mi piace (I saw the thing that i like). Never use ciò for refereing at the subject. I hope I've helped you a bit. Let me know. Bye