Question

I....... this book since morning.(read)​

Answer 1

Answer:

I have been reading this book since morning.

(This means that I am still reading the same book)

Here we have used Present Perfect Continuous tense.

Subject + has/have + been + present participle

It is frequently used with for or since.

It is used when we talk about any action that has started in the past and is continuing now.

Present Tense:

Simple: verb/verb+s + am/is/are

Continuous: am/is/are + verb + ing

Perfect: have/has + the third form

Perfect continuous: have/has been + verb + ing

Past Tense:

Simple: the second form (regular/irregular)

Continuous: was/were + verb + ing

Perfect: had + the third form

Perfect continuous: had been + verb + ing

Future Tense:

Simple: will + verb

Continuous: will be + verb + ing

Perfect: will have + the third form

Perfect continuous: will have been + verb + ing

Answer 2

Answer:

I have been reading this book since morning.