Hi,
in France, teachers are told to compare French and English when teaching grammar. you could try to use a simple image such as:
ask him to write a couple of sentences in Italian (Superman is a superhero, superman is strong and brave...), then ask him to build the sentence in English (cut all the words, and ask him to move the little papers... you see what I mean?)
As Italian and English are pretty similar in the structure of the sentence, it should be easy - i �m assuming that you teach in Italy...
then, work both in Italian and English, to make him understand how a sentence works: a suject: who the sentence talks about. a verb: BE gives details about the subject. and complements (adjectives...)
repeat that a few times with characters/people he likes, members of his family...
It worked quite well with a pupil of mine who had the same troubles!
Let me know by PM how it worked :)
Elodie