You have a fairly good chance of seeing a few Writing section items that test proper use of vocabulary, or usage. For example, what’s wrong with the following sentence?

Affect is not the word you need; effect is correct. Affect as a noun means “emotion” or “mood”; effect as a noun means “an outcome or result.” Affect as a verb means “to influence,” whereas effect as a verb means “to cause to occur.” A different example: noisome means “offensive smelling,” not noisy.

There are many tricky pairs and triads in English. Whether you’ll be faced with any particular one on the SAT is hard to predict. The best preparation is to sharpen your vocabulary. If you have some spare time, log on to www.sparknotes.com/ultimatestyle and check out our book SparkNotes Ultimate Style for a comprehensive list of commonly misused words.

Idioms are inherited quirks of language that we absorb without question but cause nonnative speakers endless trouble.

Here’s an idiom we’ve all used:

Look at this grammatically. A pronoun that refers only to humans, me, is replacing a pronoun that refers only to inanimate objects, it.

Many idioms are meant to be taken figuratively. If you tell someone “I’m going to give you a piece of my mind,” most likely you will walk away from the conversation with your brain intact. Idioms have no rhyme or reason to them: you simply have to know their meaning. Listing all possible idioms you might see on the SAT would take up the rest of this book and is a pretty low-yield investment strategy, since you won’t see more than a couple of questions at most.

One particular type of idiom is more limited and more likely to be tested. The particular meaning of certain words requires the use of a particular preposition:

Sometimes a word can be combined legitimately with more than one preposition, but the meaning will then shift. Knowing which preposition triggers which meaning is crucial to good usage:

Meant as shows intent; meant for indicates a destination. A complete and relatively short list of such “prepositional idioms” can also be found in SparkNotes Ultimate Style.

Finally, let’s consider double negatives. When we want to negate something, we use no or not:

For reasons of redundancy and idiomatic preference, we don’t use no and not in the same sentences:

Words other than no and not can indicate negation. Here’s a list of those words with their positive counterparts (which are not necessarily their antonyms). Don’t use a negative word with not or no.

Three other words are often involved in double negatives: hardly, scarcely, and barely.

Believe it or not, this is not grammatically incorrect, but it has fallen out of favor. The preferred versions are: