he b. who which d. while

STRUCTURE 53 MAKING SENSE OF SENTENCES The grass grows. This is an example of the basic unit of thought in the English language: the sentence. Sentences must have two key parts—a subject and a predicate—and express a complete thought. The subject grass names what the sentence is talking about. The predicate is a verb or verb phrase grows that tells us something about the subject. The subject of a sentence may be singular, meaning that there is only one subject. Subjects may also be compound, meaning they have more than one subject: The grass and the flowers grow. The predicate may also be singular or compound. For exam- ple, here the predicate is singular: I ate a bowl of spaghetti. In the following example, the predicate is a compound: I ate a bowl of spaghetti and drank two glasses of milk. WHAT IS A CLAUSE? Like sentences, clauses are groups of words that have a subject and a predicate. Clauses may be independent or dependent. An independent clause stands alone and expresses a complete idea as in this example: Ximena walked on the grass. When a sentence has more than one independent clause, it is called a compound sentence. In compound sentences, independent clauses are joined by a connecting word or conjunction and, but, or, for, nor, so, or yet. In the following example, the independent clauses are under- lined: Ximena walked on the grass, but she didn’t get her new shoes wet. A dependent clause does not express a complete thought: though it was wet. When a dependent clause stands alone, it is called a sentence fragment. To make a complete thought, a dependent 54 TOEFL EXAM ESSENTIALS clause needs an independent clause: Though it was wet, Ximena walked on the grass. Sentences that contain an independent clause and a dependent clause are called complex sentences. Quick tip: To identify a sentence fragment or dependent clause on the TOEFL exam, look for the following joining words, called subordinating conjunctions. When a clause has a sub- ordinating conjunction, it needs an independent clause to com- plete an idea. after because once though when although before since unless where as, as if if that until while Practice Underline the independent clauses in the following sentences. Find the answers on page 82. 1. I went for a walk downtown and mailed your letter. 2. If it is hot tomorrow, let’s go to the beach.

3. The 20-foot-tall, long-necked giraffe is the tallest living

animal on Earth.

4. The log-cabin quilt was probably designed as a way to give

a second life to unwieldy but warm fabrics salvaged from suits and coats. PARTS OF SPEECH A word can be classified as a different part of speech depending on how it works in a sentence. For example, the word quiet can be a noun, verb, or adjective; add –ly and it can function as an adverb. This table lists the parts of speech: