Carlos y Sofia le escriben una carta a su familia.
That is the answer if the verb is "escribir."
Hope I helped!
:)
Well First of all Tener que means Must
so the list will be maybe like this If I understood the Question correctly
<span>Tener que tener pastel para la fiesta = must have cake for the party
Tener que </span><span>haber adivinar para la fiesta con regalos= must have guess with gifts
</span>Tener que <span>tener favores de partido = Must have party favors
hopefully I understood the question correctly and I was a help to you </span>
Estamos
estar because this verb comes straight after an already conjugated verb
