I know the present perfect continuous is used for activity which has stopped recently or now. When it combines with for, since, or how long an activity is done, it means the activity is still happening. I did a question on a grammar book which asked me to fill the bracket with the correct tense:

I (1) (read) the book you lent me and I will return it when I (2) (read) it.

The answers for the blanks are:

 (1) have been reading 
 (2) have read 

I understand the answer for (2), but I don't quite comprehend the answer for (1). It uses the perfect continuous tense even though the activity is not stopped and it is not followed by how long the activity is. Or the clause (you lent me) indicates that the activity begins from the time the book was lent until now?


"Have been reading" is in the present perfect continuous tense. The present perfect and present perfect continuous do not require that the action has been completed. This tense is actually used to describe actions in the past that have a connection to the present. Either the action has been completed (approximately) now or it will continue — both options are possible.

The presence of for does not change the entailments of the present perfect progressive. I could say either of the following:

  1. I have been reading this book for hours, and I will keep reading until bedtime.
  2. I have been reading this book for hours, but now I'm watching TV.

In (1), the context says that the action is continuing, while in (2), the action has stopped. The pres. perf. continuous works in both cases. The common thread is that, in both sentences, the act of reading is described with respect to the present time.

One other thing: you might notice that the present perfect construction "have read" that you have in your example is not forming a connection to the present, but rather forming a connection to a future time. This is because of something special about when clauses that refer to the future, wherein the form is present tense (in this case present perfect), but the meaning is like the future tense (in this case future perfect: "will have read").

  • Is it even true that "I have [verb]ed" doesn't mark completion? If I have read the book, it means that I've completed reading it. – Pacerier Oct 31 '18 at 7:39
  • I said that the construction does not require the action has been completed. But it can be. Determining whether the act is complete depends on the context. "I have read 5 books today" means that, if there is still some day left, I could read more. "I read 5 books today" means that the day is done or you don't intend to read any more books -- it's a completed event. "I have read the book" indicates completion because there's only one book, so you can't keep going. – Kosmonaut Nov 9 '18 at 17:38

The first answer

I have been reading the book you lent me ...

just means that you are in the process of reading the book. You have begun that process and are continuing it. You have not given up, and are assuring the lender that at some point you will be able to return the book.