The document discusses the difference between the present perfect and present perfect continuous tenses. The present perfect is used to talk about completed actions or events that have a connection to the present. The present perfect continuous focuses on unfinished or ongoing actions and events and how long they have been occurring. Some verbs like "live", "work", and "study" can be used with both tenses without a difference in meaning. The present perfect is used with time expressions like "for", "since", "already", and "yet". The present perfect continuous is used with expressions like "for", "since", "how long", "lately", and "recently".