In grammar use of words that help to put forth a fact or statement as proof or evidence a reason quotBecause,quot quotDue To,quot quotSince,quot and quotAsquot Correct Ways to Say ldquoBecauserdquo quotBecausequot heads up subordinate clauses, which means if you have a clause that starts with quotbecause,quot you must also have a main clause in your sentence. A main clause is something that could be a complete sentence by itself. The main clause can come first or last if it comes last, you need a comma. Because Squiggly woke up late, he had to postpone the fishing trip. subordinate clause first, note the comma Squiggly had to postpone the fishing trip because he woke up late. subordinate clause second, no comma needed Because he woke up late. sentence fragment