Hi CB,
I wouldn't know where to start! English grammar is pretty different from Italian grammar. However, there are a lot of similar words (one example: government - governo), and several similar structures and idioms. The problem is that there are also several false friends, and lots of features that are very confusing because they wouldn't make sense in Italian.
One example is prepositions: on the net, on a pc, in a movie, in a dictionary, in a newspaper... in Italian you could use either "in" or "on" (nel, nella, etc / sul, sulla, etc.), and no one would notice (I hope so, lol). I always have to be careful to use the right prepositions in English, in Italian I pick one at random, lol.
Then there are tricky words like "any" and "some", which in Italian are both "del, delle, etc.", so you don't have to choose. The same is true of "few" and "little" (=un po'), and for "already" and "yet" (=già)... and many other things I don't remember right now.
And there are a lot more tricky things, like negative questions (we use negative questions to sound "casual" and "polite", but in English they sound completely different), genderless pronouns (in Italian it's so simple, it just depends whether the noun is masculine or feminine, so death is a "she", and hate is a "he"), etc.
Anyway, don't think Italian is simple... it's really a mess. And there are a lot of regional differences, REALLY a lot. Just think that I hardly ever speak Italian, so I wouldn't say my Italian is very good at all.