You use "no longer" in a positive sentence and "anymore" in a negative sentence. For instance: 1. I no longer talk to him. = I don't talk to him anymore. * You don't write "I don't no longer talk to him." This is incorrect because you have a double negative. That is you are saying "do not" with "no longer". Both are negative. 2. I no longer want to study English. = I don't want to study English anymore. 3. I no longer study at that library. = I don't study at that library anymore. 4. I no longer live there. = I don't live there anymore.