https://gmatclub.com/forum/due-to-vs-because-of-140393.htmlRULE 1: The expression ‘due to’ can only be used to modify nouns. Thus, you cannot use this expression to present reason for an action in the clauseRULE 2: ‘Due to’ is correct if the sentence makes sense when you replace ‘due to’ with ’caused by’. If, it does not, then use of ‘due to’ is not correctRule 3: The expression ‘because of’ is used to modify entire clauses. Thus, you can use this expression to present reason for an action in the clause.Example:
The parent-teacher meeting was canceled due to heavy rains. – INCORRECT
‘Due to’ modifies the action in the preceding clause and hence is not used correctly.The parent-teacher meeting was canceled caused by heavy rains. – INCORRECT
Note how when “due to” is replaced with “caused by”, the sentence no longer makes sense.The parent-teacher meeting was canceled because of heavy rains. – CORRECT
‘because of’ modifies the action in preceding clause, indicating why the meeting was canceled.The cancellation of parent-teacher meeting was due to heavy rains. – CORRECT
‘Due to’ modifies the noun – cancellation.The cancellation of parent-teacher meeting was caused by heavy rains.- CORRECT
Note how when “due to” is replaced with “caused by”, the sentence makes complete sense.