One of the main differences between English and Spanish negative sentences is that the Spanish create a simple negative sentence by placing no in front of the conjugated verb.
Él habla español. Él no habla español.
He speaks Spanish. He no speaks Spanish.
Nosotros bailamos. Nosotros no bailamos.
We dance. We no dance
If you translate the Spanish negative sentences word for word, it sounds funny because an English sentence uses a helping verb to make a sentence negative even though the affirmative sentence has no helping verb.
He speaks Spanish. He does not speak Spanish.
We dance. We do not dance.
You probably never even considered the word do or does as part of a negative sentence in English, but you must remember that Spanish does not use any helping verbs to make a sentence negative. They simply place a no in front of the verb. Don't try to translate the word “do” or “does” to any Spanish sentence.
The best way to create a simple negative sentence is to consider the affirmative sentence and put a no in font of the verb. If you want to write the negative sentence, “Marco doesn't play soccer,” first create the sentence, “Marco plays soccer.” Once you have the verb conjugated correctly in the affirmative sentence, add no in front of the verb and you have the Spanish equivalent to “Marco doesn't play soccer.” See the following example:
Marco juega al fútbol.
Marco plays soccer.
Marco no juega al fútbol.
Marco doesn't play soccer.
It's common to hear that Spanish sentences use “double negatives.” In reality, not every negative sentence has more than one negative word, and some negative sentences have three or four. There are certain words that have affirmative and negative versions. When a Spanish sentence is negative, there will always be a negative word in front of the verb, and any other word in the sentence that has a negative version will be in the negative even though equivalent English negative sentences often use affirmative words.
There are two ways to write a negative sentence: either with the word no followed by the conjugated verb of the sentence or with another negative word followed by the conjugated verb of the sentence. If the word no is used prior to the conjugated verb of the sentence, then if necessary one of the words from Table 1 in "Negative Words and Expressions" directly follows the conjugated verb. See the following examples:
Alguien trabaja aquí.
Somebody works here.
No trabaja nadie aquí. or Nadie trabaja aquí.
Nobody works here.
José tiene algo en la mano.
José has something in his hand.
José no tiene nada en la mano. or Nada tiene José en la mano.
José doesn't have anything in his hand.
Siempre estudiamos antes de un examen.
We always study before a test.
Nunca estudiamos antes de un examen. or No estudiamos nunca antes de un examen.
We never study before a test.
Me gusta la pizza también.
I like pizza, too.
No me gusta la pizza tampoco. or Tampoco me gusta la pizza.
I don't like pizza either.