Present Simple tense review

The simple present tense is one of several forms of present tense in English. It is used to describe habits, unchanged situations, general truths, and fixed arrangements.

• To express habits, general truths, repeated actions or unchanging situations, emotions and wishes:
  I smoke (habit); I work in London (long term -unchanged situation); London is a large city (fact / general truth)
• To give instructions or directions:
  You walk for two hundred meters, then you turn left.
• To express fixed arrangements, present or future:
  Your exam starts at 09.00
• To express future time, after some conjunctions: after, when, before, as soon as, until:
  He’ll give it to you when you come next Saturday.