1. Yo le di un regalo a mi madre el miércoles. (dar)
2. Ustedes fueron de compras el domingo. (ir)
3. Vosotros fuisteis de compras el domingo. (ir)
4. Usted vio a los estudiantes la semana pasada. (ver)
Note: In some countries, the second-person plural pronoun is "ustedes," while in others, it is "vosotros." Therefore, the correct form to use in the second and third sentences may depend on the dialect of Spanish spoken in the particular region.