5c Mary studied, but George watched television.
or one or more subordinate clauses, whose addition creates a complex sentence:
5d Mary, who wants to go to graduate school, studies whenever she has a moment.
Note that subordinate clauses here function differently. "Who wants to go to Berkeley," because it tells us about Mary, is adjectival; "whenever she had a moment," because it tells us about when she studied, is adverbial. But subordinate clauses are not limited to functioning as adjectives or adverbs. They can also act as nouns. In the sentence
6Whoever wants to go to UVic should study hard;
"whoever wants to go to UVic" is a subordinate clause but it is also the subject of the verb "should study."
Subordinate clauses differ from coordinate clauses by virtue of the the way they are joined to the rest of the sentence. Main clause is added to main clause by a coordinating conjunction, like and or or or but, which are used to join elements of equal value. "Mary and George"; " ran and played." Subordinate clauses are introduced by subordinating conjunctions or relative pronouns. If and although are examples of subordinating conjunctions. So is whenever. Whoever and Who, on the other hand, are pronouns.