Translation:The author described the city in his book.
Occupational titles are generally presumed to be Male in Duolingo. In the "Occupations" lesson, Duolingo says this:
"GENDER MARKERS RELATED TO FAMILY MEMBERS, FRIENDS AND PROFESSIONS:
As mentioned in the Family lesson notes, nouns not relating to family have no base gender:
amiko : a male or female friend dentisto : a male or female dentist
In these cases, you may choose to explicitly make a noun feminine by adding -in: amikino = a female friend dentistino = a female dentist
Choosing to do this is more common in Europe than in the US, probably due to differences between English and various European languages. In this course, we will not routinely present the feminine form of professions. However your responses using the feminine form when appropriate will be accepted as correct."
Occupational titles are generally presumed to be Male in Duolingo.
Actually, Duolingo treats occupational titles as epicene; that is, there is no gender associated with the title.
Well...for the most part; there are some exercises where they use "X-o kaj X-ino" to show both male and female X-ers. (Which is wrong, in my opinion.)
Verkisto—author. Can be female, can be male; both he and she should be accepted for the sia in this sentence.
Verkistino—author who is explicitly female.
Virverkisto/verkistiĉo—author who is explicitly male. Using vir- as a prefix is uglier, but more accepted. Using -iĉ- as a mirror suffix is more pleasing to me, but isn't as popular because that would be admitting that Esperanto isn't perfect.
Gender-based modifiers for occupational titles should be rarely used in the modern world, since for most occupations there is nothing about one's gender that would make it necessary to have a distinction.