The spelling that you learnt is correct for British English. For example: I need to practise some more. ---> verb I need more practice. -------> noun In American English, both the noun and the verb are spelt 'practice': the variant with the 's' is never used by speakers of American English. Has the spelling changed? No, it hasn't. Not yet, at least. What is happening, though, is that many younger British English speakers are beginning to adopt the American convention because they see the verb 'practise' so rarely. People who are unaware of the spelling difference are far more likely to see the verb spelt with a 'c' on the internet, in subtitles and so on, so they copy this spelling. Some people, of course, just get it wrong. I noticed a post from a young British member only today in which he wrote the noun with an 's'. That's simply a mistake. I predict that the spelling will eventually change. In a generation or two, the verb 'practise' is may well disappear. But it hasn't gone yet!

Use a dictionary that includes British and American usage. Online Collins Dictionary: https://www.collinsdictionary.com/dictionary/english/practise practise - verb REGIONAL NOTE: in AM, use practice Online Longman's Dictionary: https://www.ldoceonline.com/dictionary/practise practise - verb prac‧tise British English, practice American English /ˈpræktɪs/ Oxford Learner's Dictionaries: https://www.oxfordlearnersdictionaries.com/definition/english/practise?q=practise practise verb (US English practice)

In British English, yes. In North American English, only the second spelling is used for both the verb and noun.