"I want to send her my book."

Translation: Chcę wysłać jej moją książkę.

[Euhan1]

Isn't "ją" the dative? Why is it "jej"?

[Jellei]

No, Dative is "jej", and so is Genitive. "ją" is Accusative.

[WilliamEve8]

przesłać?

[Jellei]

Seems slightly different than "wysłać" to me, but I cannot pinpoint the (potential) difference. Added now.

[.mote.]

Is there any change in meaning or emphasis between "Chcę wysłać jej..." (the given answer) and "Chcę jej wysłać..."?

[Okcydent]

None. I personally see the latter option as stylistically better.

[.mote.]

Thanks for your reply! If/when notes are ever written for this course, I'd hope they would include some pointers about word order.

[LisaMierze]

why is "moja" used as the correct possessive form...isnt the"e" at the end of ksiazke indicative of the masculine? This is so confusing. I wish you would explain this somewhere on the site. It is not enough to memorize it.

[Vengir]

„Książkę” is the accusative form of feminine „książka”. I believe the accusative case was touched in one of the few tips and notes sections available if you are using the web version.

Otherwise, this discussion should point you to many interesting Polish topics: https://www.duolingo.com/comment/16296174