because / because of
and "because of" are used to give reasons or to indicate the
source of a situation. They answer questions asked with
the word "why."
"Because" is used with clauses. "Because of"
is used with phrases and, sometimes, single words.
starting to get nervous because he has so much work to do and
not enough time to finish it all.
(A subject and a verb come after "because.")
He's feeling a lot of stress because
of his job.
of" is part of a prepositional phrase.)
Trade Center fell down because it was attacked by terrorists.
("...it was attacked
by terrorists" is a clause. Subject = it;
verb = was attacked)
The World Trade Center fell down because
of a terrorist
("...of a terrorist
attack" is a prepositional phrase.)
I make a lot of mistakes spending money in other countries because the money is so different.
Because the world
climate is changing, polar bears are in danger of becoming extinct.