If someone were to tell this same group of people to think of an oak tree, their mental picture would be more closely alike. If someone were to tell this group to think of an old, dead oak tree, the mental pictures would be even more similar. The words oak , old , and dead all modify the word tree . The words up and quickly modify the word walks . Logically then, the function of a conjunction is to join together two or more things.
Conjunctions can join words, phrases, or even whole sentences together.
That's their job. When they join two things together, however, the result is not always the same. The use of the coordinating conjunction suggests that the order could be reversed without changing the meaning. She danced all night with Jim, but Mary went with Tom to the dance. That's the way the coordinating conjunction works.