Final answer:
The sentence 'Tú soy vieja' is incorrect. The correct form is 'Tú eres vieja'.
Step-by-step explanation:
The sentence Tú soy vieja is incorrect. The correct form of the sentence should be Tú eres vieja. In Spanish, the verb ser is used to express identity or permanent characteristics, while the verb soy is the first person singular form and means 'I am'. Since the subject tú corresponds to 'you' and not 'I', we need to use eres instead. Therefore, the correct sentence is Tú eres vieja.
Learn more about Spanish verb conjugation