Final answer:
To form negative sentences in Spanish, use 'no' before the verb.
Step-by-step explanation:
To write each sentence in the negative in Spanish, we can use the word 'no' before the verb. So, the negative form of the sentence 'El cielo es morado' would be 'El cielo no es morado.' Similarly, the negative form of the sentence 'Los carros son nuevos' would be 'Los carros no son nuevos.'
Learn more about Forming negative sentences in Spanish