We can have a picnic in Central Park não poderia ser We could have a picnic in Central Park?
We can have a picnic in Central Park não poderia ser We could have a picnic in Central Park?
acredito que isso mudaria o tempo verbal da frase
Basicamente está mudando o tempo verbal da frase de podemos(can) para poderíamos(could).
Segundo google, can is used for present or future ability, possibility, or permission, while could is used for past ability, a more hypothetical or uncertain possibility, or as a more polite request