Final answer:
The best Spanish word to use in this context is 'iban', which is the past tense of the verb 'ir' (to go), and indicates a past action of going to the park.
Step-by-step explanation:
The correct word in this context is iban.
The verb 'iban' is the past tense of the verb 'ir', which means 'to go' in English.
In this sentence, 'iban' is used to show the past action of going to the park. The correct sentence would be: 'Nataniel y yo iban al parque todos los días' (Nataniel and I used to go to the park every day).
Learn more about Use of the past tense verb 'iban' in Spanish