This is the 5364th most frequent Portuguese word.
respondem
"Respondem" means "they respond" or "they answer" in English.
Here, 'respondem' means 'answer' and indicates the action of replying to the questions being asked.
Os alunos respondem às perguntas do professor.
The students answer the teacher's questions.
In this sentence, 'respondem' is indicating that books do not provide responses in the way human conversation does.
Os livros não respondem como uma conversa.
Books do not respond like a conversation.
The word 'respondem' here signifies the act of replying to received emails quickly.