By Difference between, Countable or uncountable

Hoa Thai wrote:First, thank you for your reply. Now if you can help me a bit further, I would appreciate very much.If advice is an uncountable abstract noun, then advices must be wrong, right? (Yesterday, my father gave me his advice. Today, my mother gives me hers. I don't like their two advice...

I think what we have here is a difference between American English and British English. From what my British colleagues tell me they buy 2 lettuces and from what I know being a speaker of American English is that we buy 2 heads of lettuce. Result is: it can be used either way.