The present perfect continuous tense is used to describe an activity that began in the past and has continued up until now or recently stopped. It is formed using have/has been + verb+ing. Some key uses include describing activities that have been ongoing for a specific period of time (e.g. "I have been working for 2 hours"), activities that have been happening repeatedly over a period (e.g. "they have been going there for years"), and activities that were interrupted recently (e.g. "where have you been?"). It is not normally used with stative verbs or words like "ever" and "never".