First--

Thanks for your responses to my earlier question about a grammar text for a
writing course.

Here's a question about subordinating conjunctions.  I agree that "because"
is one, but it is commonly used as a coordinating conjunction by my
students.  For example:

        1.  He never should have gone, BECAUSE if he hadn't the whole fiasco could
have been avoided.

"When" is another example:

        2.  "He had stopped in my room to check his email, WHEN I asked if I could
question him on his opinions of
        medical marijuana."  (student sentence)

This is my question: what do we say about "because" here?  Is it being used
as a coordinating conjunction?  Or is it a subordinating conjunction that
is being used in a nonrestrictive clause rather than a restrictive one,
hence the comma, as in the second sentence below?

        3.  We went for a swim BECAUSE it was hot.
        4.  We won the battle, ALTHOUGH we lost the war.

One subordinating conjunction, while, has (according to Fowler) three
functions: one temporal, one concessive, and one contrastive.  In
        5.  Wait WHILE I run up stairs.

"while" is temporal; in

        6.  My brother lives in Manchester, WHILE my sister lives in Glasgow.
(Fowler, 4th ed.)

"while" is one of the others--both, really.  We mark the difference with
the comma.  So: are there two or more kinds of subordinating conjunctions,
as 5. and 6. suggest to me?  Or is it rather that subordinating
conjunctions operate similarly in different kinds of clauses, as in 3. and
4.?  Or are there subordinationg conjunctions that are sometimes
coordinating ones, as in 1. and 2.?  Fowler, 2nd ed.., thinks so: "_while_
(or less commonly _whilst_) is a conjunction of the kind called strong or
subordinating, i.e. one that attaches a clause to a word or a sentence, not
a weak or coordinating conjunction that joins two things of equal
grammatical value; it is comparable, that is, with _if_ and _although_, not
with _and_ and _or_."  Fowler outlines "the stages of degradation of
_while_ from a strong conjunction to a weak one."  He gives the example,
"White outfought Richie in every round, and the latter bled profusely,
while both his eyes were nearly closed at the end."  This sort of sentence
Fowler calls "the flabbier kind of journalese."  (706)

What do we say about these?

Paul