"Mój tata jest pisarzem piszącym książki o motylach."

Translation: My dad is a writer who writes books about butterflies.

[KirillKozlovsky]

Nazywam się Nabokow, miło mi.

[zagadka314]

I don't get the reference

[Dahlie5]

Vladimir Nabokov, who wrote "Lolita", had a butterfly collection.

https://en.wikipedia.org/wiki/Vladimir_Nabokov

[sarefo]

Dobranoc na cziemnosć.

(OK, that's the best I could come up with for "A good night for mothing" :P )

[PinkHill552]

Why I cannot write "My dad is THE writer who writes books about butterfiles" ?
Because we have recognized him as the writer ?

[Shamarth]

I believe that using a definite article should be accepted. Are you sure that that was the reason your sentence got rejected?

[Jellei]

It is indeed accepted.

Apparently the typo in "butterflies" was what made that answer rejected.

[pdamerval]

My dad is a writer of books about butterflies should also be accepted, as it is the most common way to convey that semantic content. The accepted translation is awkward and seldom heard.

[Jellei]

Perhaps, but we are teaching a structure, and "piszącym" is exactly the word this sentence is supposed to teach. If you don't want to go with "writing" this way, then we accept "who writes/is writing" as well, but this really should have some form of the verb.

[gkouye]

Does the Polish sentence imply that my dad is in the process of writing a book about butterflies right now? Or does it imply that he's known for books on butterflies that he has written, although he isn't writing any more now? Or both?

[Jellei]

He generally writes books on butterflies. If he was writing one (even not his first) now and we wanted to say that, that could be "piszącym książkę o motylach", but that's a very unusual thing to say. "Mój tata jest pisarzem i właśnie pisze książkę o motylach" (and just now he's writing a book on butterflies) would be my way of saying that.