The British English usage is the ending "ice" for the noun and "ise" for the verb. E.g., I would advise you that the advice is to practise the practice of grammar. Americans use "ise" in all cases.
Sorry to disagree, but I am an American, and I was taught the correct usage of each in school.
Alan...I think you meant to write that Americans use "ice" not "ise" for the word practice. (I'm from the US) Americans always use practice, not practise. (Even as I tried to write practise the spellcheck keeps trying to correct me). I wonder if the spellcheck does that if you live in the UK?
DJL...Americans never use the word "practise"...so in the US there would be no "correct usage" of each...unless you mean that it would be correct to use "practise" when communicating with a Brit.
No, I thought he was saying that Americans always say advise, even when they mean advice.