[does happen, will happen], [go, will go] - notice that the active verb doesn't change from present to future, rather there is an auxiliary added to mark the te

[does happen, will happen], [go, will go] - notice that the active verb doesn't change from present to future, rather there is an auxiliary added to mark the tense. Contrast to French where you have [vois/see, verrai/will see] and the verb itself is modified.