"Beautiful dream" is one English equivalent of the Italian phrase Bel sogno.
Specifically, the masculine adjective bello* means "beautiful" in English. The masculine noun sogno translates as "dream" in English. The pronunciation will be "behl SOH-nyoh" in Italian.
*The ending syllable -lo drops -- and is replaced by an apostrophe -- before a noun which begins with a consonant.
"Beautiful dream" in English is bel sogno in Italian.
"Beautiful horse" in English is bel cavallo in Italian.
"Beautiful disaster" in English is bel disastro in Italian.
"Beautiful woodland!" in English is Bel bosco! in Italian.
"Beautiful nephew" in English is bel nipote in Italian.
bel posto
bel viaggio
bel giardino
Bel chef
"It was a beautiful dream" is an English equivalent of the Italian phrase Era un bel sogno. The imperfect imperative, masculine singular cardinal number/definite article, and masculine singular adjective and noun -- which most famously reference a same-titled film from 1909 -- additionally translate into English as "He (she) was a beautiful dream," "It (he, she) was one beautiful dream," and "(formal singular) You were a (one) beautiful dream" according to context. Regardless of meaning or use, the pronunciation will be "EY-ra oon bel SO-nyo" in Italian.
"Beautiful vase" in English means bel vaso in Italian.
"My handsome brother" in English is mio bel fratello in Italian.