"The man likes reading History."
Translation:Του άντρα του αρέσει να διαβάζει Ιστορία.
The thing that is pleasing to the man is να διαβάζει Ιστορία.
That clause is the subject of αρέσει, but the clause contains a verb of its own, διαβάζει, and Ιστορία is the object of that verb.
Compare an English sentence such as "Meeting her yesterday was fun" -- the subject of the verb "was" is the entire phrase "meeting her yesterday", and inside that phrase, "her" is the object of "meeting".
The simple answer: because Greek lost the dative case, so it can't be in the dative.
Reading history appeals to the man -- the experiencer "ought to be" in the dative case.
When the dative case was lost, it was mostly replaced by the genitive case for pronouns and σε + accusative for nouns, at least in the standard language based on southern Greece. (In the north, the dative was (often? sometimes?) replaced by the accusative.)
But sometimes the genitive case can be used for nouns as well in places such as this -- you can have either Στον άντρα αρέσει... or Του άντρα του αρέσει.... The latter might perhaps be considered a variation of of Του αρέσει... which is extended by saying to whom it appeals, using the same case as the pronoun.
As far as I know, Του άντρα αρέσει... without the resumptive pronoun του is not possible.
No, the verb "like" in Greek has a very particular...perhaps seemingly weird... form. You'd do best to learn through doing the exercises so you get used to it.
Αρέσει/ Αρέσουν requires a personal pronoun in genitive as an object. Therefore, "Ο άνδρες" ι is not correct. You have to use "του άντρες" instead.
I hope this helps. :-) You can read more about this in the "Tips¬es for the Verb Pres 1 Skill. Here's the link:
If you follow these instructions you'll find it easier to progress and have fewer errors.
TIPS TO MAKE LEARNING EASIER + HOW TO REPORT A PROBLEM https://forum.duolingo.com/comment/22424028