When to Use Subordinate Clauses
Subordinate clauses, which can’t stand alone, have three main purposes in life. A subordinate clause can describe nouns and pronouns; describe verbs, adverbs, and adjectives; or at act as the subject or object of another clause.
Subordinate clauses that describe nouns and pronouns
A subordinate clause may give your listener or reader more information about a noun or pronoun in the sentence. Here are some examples, with the subordinate clause in italic:
The book that Michael wrote is on the best seller list. (that Michael wrote describes the noun book)
Anyone who knows Michael well will read the book. (who knows Michael well describes the pronoun anyone)
The book includes some information that will prove embarrassing to Michael’s friends. (that will prove embarrassing to Michael’s friends describes the noun information)
You don’t need to know this fact, so skip to the next paragraph. Still here? Okay then. Subordinate clauses that describe nouns or pronouns are called adjectival clauses or adjective clauses. Happy now?
Subordinate clauses that describe verbs, adjectives, or adverbs
Subordinate clauses also can describe verbs, adjectives, or adverbs. The subordinate clauses tell you how, when, where, or why. Some examples, with the subordinate clause in italic, are as follows:
Because Michael censored himself, the book contains nothing about the exploding doughnut. (Because Michael censored himself describes the verb contains)
We will probably find out more when the movie version is released. (when the movie version is released describes the verb will find)
The government may prohibit sales of the book wherever international tensions make it dangerous. (wherever international tensions make it dangerous describes the verb may prohibit)
Michael is so stubborn that he may sue the government. (that he may sue the government describes the adverb so)
More grammar terminology, in case you’re having a very dull day: Subordinate clauses that describe verbs are called adverbial clauses or adverb clauses. Subordinate clauses that describe adjectives or adverbs (mostly in comparisons) are also adverbial clauses. Adverbial clauses do the same job as single-word adverbs. They describe verbs, adjectives, or other adverbs.
Subordinate clauses that act as subjects or objects inside another clause
This one is a bit more complicated: Subordinate clauses may do any job that a noun does in a sentence. Subordinate clauses sometimes act as subjects or objects inside another clause. Here are some examples, with the subordinate clause in italics:
When the book was written is a real mystery. (When the book was written is the subject of the verb is)
No one knows whom Michael hired to write his book. (whom Michael hired to write his book is the object of the verb knows)
Michael signed copies for whoever bought at least five books. (whoever bought at least five books is the object of the preposition for)
Stop now or risk learning more useless grammar terms. Noun clauses are subordinate clauses that perform the same functions as nouns — subjects, objects, appositives, and so on.
Check out the italicized clause in each sentence. Subordinate or independent? You decide.
A. Even though Michael hit a home run, our team lost by more than 50 runs.
B. Eggworthy danced for a while, but then he said that his head was splitting and sat down.
Answer: In sentence A, the italicized clause is subordinate. In sentence B, the italicized clause is independent.