Final answer:
The best word to complete the phrase '(I know) la abuela vieja.' is 'Conozco'. It means 'to know' in Spanish.
Step-by-step explanation:
The best word to complete the phrase '(I know) la abuela vieja.' is 'Conozco'.
'Conozco' is the first-person singular form of the verb 'conocer', which means 'to know' in Spanish. It is used when referring to knowing or being acquainted with a person. In this context, the phrase translates to 'I know the old grandmother'.
Example: Yo conozco a la abuela vieja que vive al lado de mi casa. (I know the old grandmother who lives next to my house.)
Learn more about Spanish