* When you are talking about the future in relation to official timetables or the calendar, you use the present simple (`I walk’).
* When talking about people’s plans and arrangements for the future, you use the present continuous (`I am walking’).
* In `if’-clauses, time clauses, and defining relative clauses, you can use the present simple (`I walk’) to refer to the future.
1 When you are talking about something in the future which is based on an official timetable or calendar, you use the present simple tense. You usually put a time adverbial in these sentences.
My last train leaves Euston at 11.30.
The UN General Assembly opens in New York this month.
Our next lesson is on Thursday.
We set off early tomorrow morning.
2 In statements about fixed dates, you normally use the present simple.
Tomorrow is Tuesday.
It’s my birthday next month.
Monday is the seventeenth of July.
3 When you want to talk about people’s plans or arrangements for the future, you use the present continuous tense.
I’m meeting Bill next week.
They’re getting married in June.
4 You often talk about the future using the present tense of verbs such as `hope’, `expect’, `intend’, and `want’ with a `to’-infinitive clause, especially when you want to indicate your uncertainty about what will actually happen.
We hope to see you soon.
Bill expects to be back at work tomorrow.
After the verb `hope’, you often use the present simple to refer to the future.
I hope you enjoy your holiday.
5 In subordinate clauses, the relationships between tense and time are different. In `if’-clauses and time clauses, you normally use the present simple for future reference.
If he comes, I’ll let you know.
Please start when you are ready.
We won’t start until everyone arrives.
Lock the door after you finally leave.
6 In defining relative clauses, you normally use the present simple, not `will’, to refer to the future.
Any decision that you make will need her approval.
Give my love to any friends you meet.
There is a silver cup for the runner who finishes first.
7 If you want to show that a condition has to be the case before an action can be carried out, you use the present perfect for future events.
We won’t start until everyone has arrived.
I’ll let you know when I have arranged everything.