I have a question regarding the following excerpt:
"Both "¿Por qué no...?" and "Mejor no..." followed by El Presente are more frequently used in speech than their equivalent forms using the imperative:
Vayamos a la playa.
Let's go to the beach! (affirmative command)
No vayamos a la playa.
Let's not go to the beach! (negative command)"
My understanding is that whilst 'vayamos' is the negative imperative form of 'ir', 'vamos' is the affirmative form, contrary to the above.
Is there a situation where we would use the subjunctive 'vayamos a la playa' instead of the affirmative imperative 'vamos a la playa' to express the same command?