[EnglishTeacher79]

I have a question about the transition signals (for reasons) that I hope Susan and others can address. People view "for" as a coordinating conjunction, while "because", "since" and "as" as a subordinating conjunction. I understand (I think) the difference between coordinating and subordinating conjunctions but I'm not sure why "for" is a coordinating conjunction while the other three are subordinating. As far as I can tell, when I think of sentences with "because", "since" or "as", these could easily be substituted by "for". Am I right on this? If so, what makes "for" a coordinating conjunction and not a subordinating conjunction, etc?

Thanks!