"He answers no."

Translation: Ele responde não.

[Agovoni17]

Why is resposta incorrect?

[LelandSun]

"resposta" is the noun "answer". "responder" is the verb meaning "to answer". "responde" is its third-person singular present tense conjugation.

[Barbeito]

it is normal in Portugal to insert "que" before reported speech.

[JuddCheatw]

That is what I thought, which is also true in Spanish. Is it really even correct or common in Brazilian Portuguese to omit "que" in this case?

[LelandSun]

"Ele responde que não" is accepted as of June 2017.