I. Prediction will

4. Present Simple.

We can often use either the Present Simple or will to talk about future events that are part of some timetabled or programmed arrangement or routine. However, we prefer the Present Simple for fixed, unchangeable events:

e.g. Does/ will the sale finish on Thursday or Friday? BUT The sun rises (the train leaves) at 5.16 tomorrow.

NB. We normally use the Present Simple, not will in time clauses (with conjunctions such as after, before, by the time, when, while, until, as soon as), and in conditional clauses (with conjunctions such as if, in case, provided, suppose, unless, etc.)

e.g. I’ll let you know when I decide.

If you call her, give her my regards.

Remember, however, that when when is used as a question word (not as a time word), we use future forms.

e.g. I’m not sure when they will visit us.

We also use future forms with if (=whether) when it is used after expressions which show ignorance, uncertainty, doubt, etc. such as I don’t know, I wonder, I doubt, etc.

e.g. I don’t know if/whether he’ll move house.

I doubt if/whether she’ll pass her exams.