A scientific study by a blue-ribbon panel of experts found that 90 percent of all the errors in a sentence occurred because the verb was misidentified. Okay, there was no study. But it is true that when you try to crack a sentence, you should always start by identifying the verb. To find the verb, read the sentence and ask two questions:
What’s happening?
What is? (or, What word is a “giant equal sign”?)
If you get an answer to the first question, you have an action verb. If you get an answer to the second question, you have a linking verb.
For example, in the sentence
Archie flew around the room and then swooped into his cage for a birdseed snack.
If you ask what’s happening, your answer is flew and swooped. Flew and swooped are action verbs.
If you ask, what is, you get no answer, because there’s no linking verb in the sentence.
Try another:
Lola’s new tattoo will be larger than her previous 15 tattoos.
What’s happening? Nothing. You have no action verb. What is? Will be. Will be is a linking verb.
You may hear English teachers say, “the verb to sweep” or some such expression. But to sweep is not actually a verb. It's an infinitive.
The most important thing to know about infinitives is this: When you pop the question to find the verb, don’t choose an infinitive as your answer. If you do, you’ll miss the real verb or verbs in the sentence. Other than that, forget about infinitives!
Okay, you can’t forget about infinitives completely. Here’s something else you should know about infinitives in formal English: Don’t split them in half. For example, you commonly see sentences like the following:
Matt vowed to really study if he ever got the chance to take the flight instructor exam again.
This example is common, but incorrect. Grammatically, to study is a unit — one infinitive. You’re not supposed to separate its two halves. Now that you know this rule, read the paper. Everybody splits infinitives, even the grayest, dullest papers with no comics whatsoever. So you have two choices. You can split infinitives all you want, or you can follow the rule and feel totally superior to the professional journalists. The choice is yours.