When you answer a negative question in Spanish usually use the word no twice?

In Spanish, it is common to use two negative words to form a double negative, but it not done when replying to negative questions. For questions already formed in the negative it it normal to only reply with one negative. Here are a few examples

Negative Question

"¿No estás leyendo un libro?" (Weren't you readind a book?)

Correct Response

"Sí, estoy leyendo el libro" // (Yes, I am reading the book.)

Negative Question

"¿No viste al perro de Juana ayer?" (Didn't you see Juana's dog yesterday?)

Correct Response

"No, no vi al perro" /// (No, I didn't see the dog/)

Negative Question

"No es necesario traer nada, ¿verdad?" (You wouldn't have to bring anything, right?)

Correct Response

"¡Claro que no. No es necesario!" (Absolutely not. You didn't have to!)