in the statement 'luego fernando y yo fuimos a la tienda de equipo deportivo para mirar patines' is either in the preterite in the ser sense or in the ir sense. Explain how we know this.

In the statement "luego fernando y yo fuimos a la tienda de equipo deportivo para mirar patines" (later, Fernando and I went to the sports equipment store to look at roller skates), the verb "fuimos" is conjugated in the preterite tense in the "ir" sense.

We know this because:
1. The verb "ir" (to go) is used in the sentence to indicate the action of going to the store.
2. The preterite tense is used to express completed actions in the past.
3. The verb "fuimos" is conjugated in the first-person plural (we) form, which matches with the subject "Fernando y yo" (Fernando and I).

Therefore, "fuimos" indicates that the action of going to the store happened once in the past, and it is conjugated in the preterite tense in the "ir" sense.