In a negative Spanish sentence, one negative must appear immediately before the verb (and any accompanying direct or indirect object pronouns).
Yo no quiero ensalada. - I do NOT want salad.
Yo no soy médico. - I am not a doctor.
Yo no tengo dinero. - I don't have money.
Ellos no están tristes. - They are not sad.
Spanish also has many other negative words that are used along with "no" or without it.
nada - nothing
nadie - nobody, no one
ninguno - none, no one
ninguna - none, no one
ningunos - not any
nunca - never
jamás - never
tampoco - neither, not either
ni tampoco - nor
These other negatives may appear somewhere after the verb as in the examples below.
Ella no durmió nada.
She did not sleep at all.
El no sabe nada.
He doesn't know anything.
Remember to convert indefinite words (i.e, “something”, “anybody”, etc.) to their negative equivalents and to avoid the plural form of "ningún" unless it modifies a noun which is always used in the plural (e.g., ningún libro, but ningunos pantalones):
No tenemos ningún diccionario.
We don't have any dictionaries.
Video
To make a statement negative, place a no immediately before the verb. For example:
Somos americanos. —> No somos americanos.
Tengo tiempo. —> No tengo tiempo.
Use ni as the negative of "y".
No tengo tiempo ni energía.
¿Tienes otro examen? No, no tengo exámenes hoy.
Do you have another exam? No, I don't have any exams today.
Note: There are no equivalents for "don’t" and "doesn’t" in Spanish.
¿Eres cantante? No, no soy un /una cantante.
Are you a singer? No, I am not a singer.
El portugués no es fácil.
Portuguese is not easy.
Los ingleses no hablan mucho.
Englishmen do not speak much.
Vive en Colombia, pero no es colombiano.
He lives in Colombia, but he is not Colombian.
Mixing Negative and Affirmative Words
Unlike English, Spanish does not normally mix negative and affirmative words.
Juan no necesita algo. (incorrect)
Juan doesn't need anything. (correct)
Juan no necesita nada. (correct)
Juan doesn't need nothing. (incorrect)
No tengo nada que hacer. (correct)
I don't have nothing to do. (incorrect)
Use of Double and Triple Negatives
Unlike English, Spanish allows for the use of double and triple negatives in one sentence.
No tienes nada que hacer.
You don't have anything to do.
Ese niño no se lleva bien con nadie.
That boy doesn't get along well with anyone.
Gabriel nunca ha contribuido nada a la clase.
Gabriel has never contributed anything to the class.
Nunca debes hablar con ningún extraño.
You should never speak to any stranger.
¿No tienes nada que decir?
Don't you have anything to say?