Presente simple why and because?

The teacher has sent several students home because they cheated on the quiz. Some students cheated on the quiz. This was later discovered (by the school / teacher) and consequently they were suspended (implied) and sent home. We do not knowwhenthe students cheated, but presumably it was not on the same day they were sent home. The teacher has sent several students home because they have cheated on the quiz. Some students were caught cheating on a quiz and they were sent home. Both actions, cheating and being sent home, seem to have taken place on the same day. Of the two sentences I prefer the first, using the present perfect for both actions is acceptable but the act of cheating clearly precedes the teacher's decision, which places it firmly in the definite past (even if we are not told "when" it happened). Shareimprove this answeransweredNov 2 '13 at 7 : 49Mari - Lou A1Downvoter, anonymous as always, the answer is "inaccurate" or my explanation is unsatisfactory? Which one, please? –Mari - Lou ANov 4 '13 at 7 : 37 + 1 since your answer isn't any worse than the other answer in this thread. (Though, both answers have errors. ) Yes, both OP's examples are acceptable and basically mean the same thing : the reason the students have been sent home is because they had cheated earlier. Your error is : in both versions, the cheating could have happened either on the same day or days before that day of being sent home. Usually, though, the teacher catches the students cheating on the quiz and then the teacher sends them immediately home. (Some pedants might erroneously think the 2nd version requires "had cheated".