as, because and since (reason)

[as/because/since + clause + clause
clause + as/because/since + clause]

  • Because is used when we give the reason for something.
      Because I was ill for six months I lost my job.

    If the reason is the most important idea, we put it at the end of the sentence.

      Why am I leaving? I’m leaving because I’m fed up!
  • As and since are used when the reason is not the most important idea in the sentence, or when it is already known. Since is more formal.
    As- and since-clauses often come at the beginning of the sentence.
      As it’s raining again, we shall have to stay at home.
      Since he had not paid his bill, his electricity was cut off.