How to request something in English with example conversation

(Ravi meets Mega and requests her to lend him a library

ticket and a pen. Later, Mega makes a request to the Librarian.)

Ravi    : Good morning, Mega.

Mega:   Hello, Ravi! Good morning. Come in and sit down.
Ravi    : Are you going out somewhere?

Mega:    Well, I was planning to go to the library
Ravi:    I too wanted to go to the library. But I
haven't got a library ticket. Can you
lend me one?
Mega: Certainly. Here you are.
Ravi:  Thanks. I'm sorry to bother you. But I
forgot to take my pen. Could you spare
one for me?
Mega: Sure. Take this one.

(At the Library)

Mega   : Can I borrow this book, please?
Library

Assistant: I'm sorry. That's ^a reference book.
You can't borrow it.

Mega   : I need it only for a day.
Library

Assistant: Please talk to the Librarian.

(At the Librarian's office)

Mega   : Good morning, sir.
Librarian: Good morning.

Mega   : Sir, may I borrow this book for a day?

I know it's a reference book. But it'd
be a great help if I could borrow it for a day.

Librarian: Normally reference books are not
issued. But I'll permit you to take it for a day.

Mega   : Can I take it now?

Librarian: No, not now. You can borrow it at
seven in the evening. And you must
return it at nine tomorrow morning.

Mega: I'll do that, sir. Thank you very much.
Librarian: You're welcome.