"It has been heard that the author is writing a book."
Translation:Ακούγεται ότι ο συγγραφέας γράφει ένα βιβλίο.
Ακούγεται ότι η συγγραφέας γράφει ένα βιβλίο was not accepted. It looks like the noun can be either masculine or feminine (word ref link below), so is it wrong because the article should not change (although it seems to for other nouns) or should the feminine be added as an acceptable answer? http://www.wordreference.com/gren/%CF%83%CF%85%CE%B3%CE%B3%CF%81%CE%B1%CF%86%CE%AD%CE%B1%CF%82
Check this is important: these are one of the nouns that don't change endings f.e The journalist ο δημοσιογράφος or η δημοσιογράφος ,the lawyer could be ο δικηγόρος or η δικηγόρος, doctor ο γιατρός or η γιατρός so is the author ο συγγραφέας or η συγγραφέας. That means these nouns the gender of these nouns depends from the article in front of them without changing the endings. But there are also the normal job exceptions like the teacher f.e which are ο δάσκαλος for men η δασκάλα for women :D i just tried to explain them as simple as i could... I have more examples to tell but i just gave you the general idea :D