'Sei bella' is an Italian equivalent of 'You are beautiful'. Italian language speakers may choose not to use subject pronouns, such as 'tu' ['informal singular 'you'], other than for clarification or emphasis. Here, the verb form in the second person singular makes clear the subject. The phrase is pronounced 'seh BEHL-lah'.
"Beautiful women!" in Italian is Belle donne! in Italian.
Bella o bellissimo
"Beautiful sisters" in English is belle sorelle in Italian.
Beautiful gift in Italian is "bel regalo"
"Beautiful horse" in English is bel cavallo in Italian.
"Beautiful night" in English is bella notte in Italian.
"Beautiful mommy!" in English is Bella mamma! in Italian.
"Beautiful mountains!" in English is Belle montagne! in Italian.
"Beautiful walls!" in English is Bellissime mura! in Italian.
Beautiful place in Italian means "posto bello"
"Beautiful woodland!" in English is Bel bosco! in Italian.
"Beautiful moments!" in English is Bei momenti! in Italian.