Answer:
You conjugate verbs when you want to say the verb without the 'to' in front of it. For example: nadar (to swim) but conjugated : nado (I swim)
Yo: Nado
Tu: Nadas
Ellos/Ellas: Nadan
Nosotros: Nadamos
El/Ella/Ustedes: Nada
Vosotros: Nadais
Answer:
Nosotros llamamos a un doctor.
Explanation:
Tu llamas a Mateo. ¿no? is grammatically incorrect, since there should be a comma instead of the period. Yo llamo Mateo también is totally incorrect, as well as Ella llama Roberto. Btw I'm a native Spanish speaker, so I'm 99% sure that's the right answer.