Hi! Here’s how to say those words in Italian:

• hi: ciao
• how: come
• are: sei (singular informal), siete (plural), or è (singular formal "you" or "he/she/it")
• you: tu (informal), Lei (formal), voi (plural informal or formal)

If you want to ask "How are you?" in Italian, you say: "Come stai?" (informal) or "Come sta?" (formal).