3. Some verbs have the idea of a long time - wait, work, travel, learn, play. These verbs can often be found in the Present Perfect Continuous: I've been waiting all day.
4. Some verbs don't have the idea of a long time: find, start, buy, die, lose, break, stop. It is unusual to find these verbs in the Present Perfect Continuous: My cat has died. My iPad's broken. I've bought a puppy.