472. The future denotes an action or state that will occur hereafter.
a. The future may have the force of an Imperative (§ 449.b).
b. The future is often required in a subordinate clause in Latin where in English futurity is sufficiently expressed by the main clause.
Cum aderit vidēbit.
When he is there he will see.
(cf. § 547).
Sānābimur sī volēmus. (Tusc. 3.13)
We shall be healed if we wish
(cf. § 516. a)
Note— But the present is common in future protases (§ 516.a, Note).