The SAT exam contains a section on identifying sentence errors. The exam gives you several sentences to choose from: usually A, B, C, D, E, with E being "no error." The test requires you to find the answer that contains a mistake. While every section is important on the exam, you should not spend a large amount of time on this portion of the test because other sections will require more time and focus. Professionals offer several approaches to identifying sentence errors in the SAT practice exam.
Choose the obvious. You are presented with several sentence choices in this section of the practice. Read each sentence carefully but quickly. Often, people are so intent on finding the correct answer that they fail to see what is right in front of them. Glance over each sentence quickly. Very often the error will jump out at you.
Read the sentences aloud. You can only do this during the practice; you won't be permitted to read aloud during the actual SAT exam. Reading the sentences aloud may help you hear the mistake in the sentence. Read the sentence slowly, using the punctuation to guide you where to pause and where to stop. A good rule of thumb: If it sounds weird, it is most likely grammatically wrong.
Look for common mistakes. Most people know the common grammar rules such as subject-verb agreement and confusion with adjectives and adverbs. Train yourself to hone in on these common errors. Many of the sentences in this section of the SAT are deceptively common grammatical errors. For example: "There is two pens, a piece of paper, and a calculator on each desk." The correct sentence should read "There are two pens ... " The subject-verb agreement error is a common one and can be easily overlooked. Train yourself to watch out for such errors.
Watch for use of slang and idioms. People in different parts of the country speak differently. Some people say "He lives on Hill Street." In other parts of the world, people will say, "He stays on Hill Street." Recognizing that the second sentence is an idiom will allow you to choose it as the sentence containing an error.
Correct errors that you find while taking the SAT practice. Make it a practice to correct errors as you find them because this will help you remember the grammar rules. Jot down grammar rules that are new to you and look them up in a grammar book.
Recall that some questions on the practice exam do not contain an error at all. Try not to agonize over sentences that you think have no errors because they probably don't. In this case, you should use E as the answer -- no error.