"They read me a book."
Translation:Αυτοί μου διαβάζουν ένα βιβλίο.
Does "Αυτοί με διαβάζουν ένα βιβλίο " mean the same ?
No. It doesn't mean anything. It tries to give the verb διαβάζω two direct objects, but the verb can only take one direct object.
It's as nonsensical as "I see him the book". You can "see him" or "see the book" but you can't "see him the book"; the verb can only take one direct object.
If they read the book to you, that's an indirect object, so you need μου and not με there.
Yes, Greek lost the dative case except in a few fixed expressions.
In standard Greek, it was replaced by the genitive case when using pronouns, but by the accusative case in the north. (When using nouns, then one usually uses the preposition σε + accusative.)
So you will find things such as μου δίνει, μου λέει, μου διαβάζει for "he gives me, he tells me, he reads to me" with genitive in standard Greek for what would be dative in other languages.
I'm not sure whether weak/strong is standard terminology, but the short forms of pronouns are used in close connection with a verb: right before it in the indicative, right after it in the imperative.
The long forms of pronouns are used by themselves (e.g. as the answer to a question), as the object of a preposition, or for emphasis (e.g. "he sees ME [and not anyone else]").
French has similar double forms for its pronouns.
I indicated the used pronoun:
And what about αυτές? Marked wrong...
Please always quote your entire answer when you have a question about why it was not accepted.
There are accepted answers that include the word αυτές, but without knowing what you wrote, we have no idea what might have gone wrong for you.
https://sun9-48.userapi.com/c855336/v855336966/15a7ab/mDkSkBGtHEA.jpg It was hard to catch this exercise again, but I finally made the screenshot. I tiped very carefully, didn't change input language on keyboard. What's wrong with it? :(
Thank you LadyRovina for the screenshot!
That does seem to be one word order where αυτές is not accepted so far. I've added it now. (It may take a couple of days before it's accepted on the live site.)
And a lingot to you for finding the sentence again and showing us your screenshot!
Why is the accent on βίβλίο at the last syllable and not the first?
It's not on the last syllable; it's on the next-to-last (penultimate) syllable: βι-βλί-ο.
And the accent mark is written there because that's where the word stress is in that word. The word is pronounced vee-VLEE-oh with stress on the next-to-last syllable.