Most Italian consonant sound the same as in English. However, there are a few spelling peculiarities you should take notice of:
c before an e or an i is always pronounced soft
ch is always pronounced hard, as in the letter k
ca, co, and cu are always pronounced hard
g before an e or an i is always pronounced soft
gh is always pronounced hard
ga, go, and gu are always pronounced hard
When g comes before a, o, and u and before consonants it sounds like the g in go. When g comes before e and i it sounds soft like the g in gelato.
sc like pesce, sciopero, and scempio is soft
Sch like scherzo, schettini, bruschetta is hard (like k)
Two other tricky sound combinations are gl and gn.
gn like gnomi is pronounced soft, as in gnocchi (where the g is soft but the ch is hard)
Another important difference is with double consonants. In English, it usually makes no difference but in Italian it does. A double consonant is pronounced over a longer period of time than a single consonant. You already know one example: the pronunciation of pizza.
For some consonants in particular: t,d,c,g,p and b there is no way to lengthen the consonant sound. Instead you stretch the holding period before you release the consonant – for instance there is a difference in Italian between fato (fate) and fatto (fact).
Some more examples:
eco (echo) and ecco (here is)
ala (wing) and alla (to the)
nono (ninth) and nonno (grandfather)
poso (I pose) and posso (I can)
The most problematic double consonant is the Italian pronouciation of the letter r – The English language has nothing like that and only people really fluent in Italian can master.
caro (dear) and carro (kart)
It can be difficult for beginners to pronounce words like:
birra, chitarra, ramarro, corro, carro, corrida, and many more...
More on R Pronunciation ( play the second recording to hear the pronunciation )
Single R - R singola is relatively easy to pronunce
Most people already know how to pronounce:
Learn Italian: Consonant pronunciation