[Nightedge]

-There is an alien who is called Einstein __ John's Japanese book.

Does it make any sense if I use on, without any context?

[susan53]

By the choice of preposition you create the context - language makes no sense out of context.

If you say There's an alien... on John's book I understand that a real alien is standing or sitting on John's book. Fine if the context is a science fiction film and the sentence is spoken by someone who has just seen the alien (or in real life if Star Trek got the date of the First Contact wrong....)

If, on the other hand, the context is that you're describing one of the book's characters, then the sentence must be There's an alien... in John's book.

[Nightedge]

Good answer. Thank you.

I was thinking about a sentence like this

-The book has an interesting cover. On (not IN) this cover, there is a monster.(=a picture of a monster)

But I think

-There is a monster on the cover of the book.

is too verbose, so can I just say

-There is a monster on the book.

to mean the same thing?

[susan53]

You see why you can't ignore context?

No - in this context, when you're talking about the cover, you must say eg John's book has an alien on the cover/front / There's an alien on the cover/front of John's book.

You can't just say on John's book.

[Nightedge]

Good answer. Thank you.