Well, english is tough and unfortunately not a precise language, so translating can be hell.
Some depends on which of the 8buhzillion ways you're using it. It's as bad as up when it's not the opposite of down (don't get me started!) and the one that my Italian teacher loves:
Get.
Someone, something is as Francis mentioned: when it's a subject or object, then you use alcune or qualche--Some would say that yaddi yaddi.
I want some bread or He took some of the cake is the di + mode. So, when it's an adjective "some bread" then it's di +
If you want to stay safe, don't get into
some as, "Boy, you've got some hot avatar!" oy.