Phrase, Sub Clause, and Main Clause often confuse untrained eyes. In fact imperfect understanding of this topic is one of the pitfalls commonly found in toefl problems. The sentences contained the slides are taken from Carol King & Nancy Stanley's TOEFL book.

1. Complex Sentences:
step-by-step introduction
by Arief Firdaus

2. Main Clause & Sub Clause
• A complex sentence contains at least two clauses: a main clause
and a subordinate clause.
• A subordinate clause, which is dependent on the main clause for its
meaning, may function in a sentence as an adjective, an adverb, or
a noun.
– an Adjective Clause (relative clause) usually begins with a pronoun,
such as who, whom, whose, that, which, were, or when, and
immediately follows the noun or pronouns it describes.
– An Adverb Clause begins with adverbial conjunction, such as because,
although, if, or while, and is frequently found at the beginning or at
the end of a sentence.
– A Noun Clause begins with the word that or question word, such as
why, what, or how, and function in a sentence in any of the ways that
a noun can.

3. Main Clause or Sub Clause?
______1. it started to rain
______2. after the runner fell down
______3. before the telephone was invented
______4. she left because of you
______5. what you said to me
______6. a singer performed after dinner
______7. she has been crying a lot
______8. exercise promotes health
______9. that apples are very nutritious
______10. winning is not everything
______11. whom he saw at the theater
______12. walking develop leg muscles
______13. while the choir was singing
______14. if prices continue to climb
______15. they arrived after the deadline

4. Sub Clause or Phrase?
_____1. before finishing dinner
_____2. if the doctors operate soon
_____3. whom the committee chose
_____4. after the last class
_____5. as the sun set behind the hill
_____6. standing in the long line
_____7. exercising every morning
_____8. which the driver hit
_____9. during the president’s talk
_____10.that he had gone bankrupt
_____11.a self-correcting type writer
_____12.what he did during the holidays
_____13.as soon as it is over
_____14. an inexpensive Japanese model
_____15.driving 120 kilometers per hour

5. Sub Clause, Main Clause, or Phrase?
______1. the water is used for irrigation
______2. which is used to make chewing gum
______3. a famous talk show host
______4. her hopes for the future
______5. the population increased greatly
______6. a brain infection causing jerking
______7. the fourth largest city of Indonesia
______8. several different writing systems
______9. when the radio was invented
______10.the first ships were only logs
______11.walking burns many calories
______12.alligators living in Florida
______13. mollusks live in shell for protection
______14. a boat floating down the river
______15. staying busy makes the time fly