I was trying to explain to a friend of mine (who is not Italian) the differences between these sentences, but I discovered I may not.
Mi sono mangiato una pizza ai quattro formaggi.
Ho mangiato una pizza ai quattro formaggi.
I was thinking the first was used as emphasis, but I have the habit to use the first instead of the second sentence, which means I am overusing that kind of sentence, or it's not really used as emphasis.
Is the first sentence really used as emphasis, or does it have a different use?
I know that a beginner in Italian should probably stay away from the first type of sentences, but my friend asked why I use the first sentence when she would expect me to use the second one.
Probably, if I were able to find the equivalent of mi sono mangiato una pizza ai quattro formaggi in American, I would help my friend better, but I would like better to give an explanation of when to use the first type of sentence.