The present perfect continuous is formed with the present tense of the verb have + been + the present participle of the main verb (root + -ing).
In the above examples, notice that the duration of the action is often indicated by time expressions such as for the last few hours/days/weeks.
When using the present perfect continuous, it's important to remember that the action is unfinished or has recently been finished. The present perfect continuous can also be used with adverbs of frequency like always, constantly, and continually to express annoyance or criticism. For example, if someone says, I have been working hard for the last few weeks, it implies that they are currently working hard, and it has been ongoing for a certain period of time. On the other hand, if someone says, I have constantly been working hard for the last few weeks, it implies that they have been continually working hard, and it may be seen as a criticism or annoyance.
Students often confuse the present perfect continuous and the present perfect simple. While they are both used to talk about actions or states that started in the past and connect to the present, the present perfect continuous tense emphasises the duration of action. They have been repairing the heating system since this morning (ongoing). In contrast, the present perfect simple tense emphasises the completion of an action They have repaired the heating system (completed). Note, though, that in some cases, we can use either form, and the meaning stays the same: I have been working here for 10 years. I have worked here for 10 years.
Verbs of mental process describe cognitive mental actions, such as think, believe, know, like, and understand. They are typically stative verbs. Therefore, it is incorrect to use the present perfect continuous with verbs of mental process. An exception is the verb think.
