From an outsider, I think advice and suggestion have similar meanings.
But I don't understand why the noun suggestion is countable whereas advice isn't. We can ask:
- Can you give me two or three suggestions on how to improve my English?
But not
- Can you give me two or three advices on how to improve my English?
In order for sentence 2 to be considered grammatical, we have to say
- Can you give me two or three pieces of advice...
Which seems redundant to me.
Is there an explanation behind this difference?