I am going to fly to Paris tomorrow. Be going to Prior plan in progress Progressive form of be going to Don't call me at nine because I won't be home. I am going to be studying at the library. My wife has an appointment with a doctor. Dr. Who next Monday.
Future time words Events that are definite schedule or timetable.
Present Simple instead of Future Simple Classes begin next week. Leave Come,Return Present Simple or, occassionally, Present Perfect, are used in the Time clauses. Present Perfect emphasises on the completion of the act in the time clause. Present Simple instead of Future Simple. Bob will come soon.