Educated guessing is always better than blind guessing. Whenever you guess, try first to eliminate some of the multiple-choice answers to improve your odds of guessing correctly. Take a look at these sample answers:

You can probably figure out from these answer choices that there is a comma placement error. Choices A, B, and D all give versions of the same sentence with different comma placement. Choice C, attempting to lure you off the right track, offers a comma-less version of the sentence with nonsensically altered verb tenses.

Can you eliminate any of these answer choices? Well, choice C looks like a prime candidate for elimination because it makes little sense. Choice D also looks like it can go because of the comma placed after “When,” which leaves the word dangling at the beginning of the sentence. If you can eliminate either or both of these, you greatly increase the chance that you’ll pick the correct answer, which is B.

Quite often, you will encounter questions that involve more than one error. While these questions may seem harder to answer than single-error questions, you can benefit from the multiple errors when trying to eliminate answer choices: if you can’t spot one error, you might spot the other.

Instead of tackling all the errors at once, you’ll have an easier time picking them off one by one. Let’s use the following example:

These sentences contain two variations. If you focus on Cathy and her friends, you realize that you should eliminate choices A and C for incorrect apostrophe placement. Now you’ve narrowed your options to B and D, which respectively use “there” and “their” as possessive pronouns. If you don’t know the difference between the two, you have a 50 percent chance of guessing the right answer. If you do know the difference (and you will, after you read the Usage/Mechanics chapter), you know that “there bags” is incorrect and that the correct answer is therefore D.