"You're extremely beautiful" is an English equivalent of the Italian phrase Sei estremamente bella. The second person informal singular present indicative, adverb, and feminine singular adjective may be said to a speaker's family member, friend, or peer. The pronunciation will be "SEH-ee ey-STREY-ma-MEN-tey BEL-la" in Italian.
"You're extremely stupendous!" is an English equivalent of the Italian phrase Sei estremamente stupendo!
Specifically, the verb sei is "(informal singular you) are". The verb estremamente means "extremely". The masculine adjective stupendo translates as "stupendous".
The pronunciation will be "sey ey-STREH-mah-MEHN-tey stoo-PEHN-doh" in Italian.
Molto bello / Molto Bella
Mia sorella è molto bella in Italian means "My sister is very beautiful" in English.
una canzone molto bella
"Very nice bicycle!" in English is molto bella bicicletta! in Italian.
Molto in Italian means "very" in English.
"It is very beautiful," "She is very beautiful," and "You are very beautiful" are all possible literal English equivalents of the Italian phrase È molto bella. Whatever the meaning as determined by context, the pronunciation always will be "eh MOL-to BEL-la" in Italian.
È molto... in Italian is "He (or she, it) is very..." in English.
Molto giocoso! in Italian is "Very merry!" in English.
Molto caldo in Italian means "very hot" in English.
"Very good!" in English is Molto bene! or Molto buono! in Italian.
Molto.
"Yes, very beautiful!" is an English equivalent of the Italian phrase Sì, molto bella! The affirmative, adverb, and feminine singular adjective may be heard said about a female or something gendered feminine in Italian. The pronunciation will be "see MOL-to BEL-la" in Italian.