Before I started teaching grammar, I had no idea what infinitives were. Sure, I had heard of them, but they seemed like subject matter for grammar cocktail parties (split infinitive anyone?). No thank you! I thought.

I had never learned about infinitives in my grammar classes, and I was getting by just fine. So when I became a teacher myself, I shied away from them for the first few years. There was so much to teach already!

But then I started really getting the hang of grammar, and my lessons began to move more rapidly. I found myself having extra time at the end of the school year to keep going. There was no longer any excuse to ignore infinitives, not to mention gerunds and participles, which we’ll get to soon enough.

So if you’re not content to relegate infinitives into an obscure Jeopardy category, then this is the lesson for you!

Let’s put this in context with an example. Be sure to download the grammar memorization questions as a cross-reference. And don’t hesitate to jump through the other lessons for review. They are all linked in the table of contents found in the introduction to this series.

SAMPLE LESSON

Infinitives are generally easy to recognize because they follow a predictable pattern: to + verb. Let’s find the infinitive in the following quote by Queen Elizabeth. 

“There is nothing about which I am more anxious than my country, and for its sake I am willing to die ten deaths, if that be possible.”

So maybe she exaggerated a little, but it’s still a good quote, especially for our purposes. “To die” is an infinitive because it follows the “to + verb” pattern.

Okay, that’s basic enough, but to really understand infinitives, we have to put them into the fuller context of language. It’s not enough to just recognize them. We need to think about them in connection to the parts of speech. Though they look like verbs, they are not. Rather, infinitives can serve as nouns, adjectives, and adverbs. When nouns, they can have multiple noun jobs: subject noun, predicate noun, object of the preposition, indirect object, and direct object.

In the example above, “to die” functions as a noun, and its jobs is that of a direct object because it answers the verb what question.

Am willing what?—to die (DO)

What kind of direct object?—infinitive direct object (IDO)

Given that infinitives are made from verbs but do not act like verbs, they are classified as verbals. Verbals themselves are not a part of speech, just as infinitives are not. They are simply one of the seemingly endless grammar classifications out there. Everything need a name, I guess.

Now for the diagram. Though it would be fun in a teacher-kind-of-way to diagram the whole sentence, we’re not ready for that yet. (The sentence structure is far beyond our current lessons.) Let’s content ourselves with diagramming just the infinitive. That’s the important part.

The top portion looks like the familiar format for a prepositional phrase. Given that “to” is often used as preposition, this makes perfect sense to my students. They just need to be reminded to look closely at the object of “to.” If the object is a noun or a pronoun, then they have found a prepositional phrase. If it’s a verb, then they have found an infinitive.

The long vertical line with the two “feet” beneath it is generally referred to as a pedestal. We use pedestals when the infinitive goes on the main horizontal line.

In many cases, infinitives consist of more than “to + verb.” When that happens, we call it an infinitive phrase, and we can classify and diagram the phrase the same way we would if the verb really were a verb. In our example, we would use this script to finish the infinitive phrase.

To die what?—deaths (DO)

How many deaths?—ten (Adj)

That phrase would look like this as a diagram.

Here’s the catch: “deaths” is not really a direct object, nor is “ten” really an adjective because they are part of the infinitive phrase. So when we classify them, we don’t need to give them individual labels. We can just put brackets around them to show they are connected to the infinitive.

PRACTICE SENTENCES

Although we will never know if Queen Elizabeth really was willing to die ten times for her country, we do know that she was willing to kill multiple times for it. The martyrdom of Saint Edmund Campion is but one example. Elizabeth had him hanged, drawn, and quartered for spreading the Catholic faith, which she deemed treasonous.

Let’s use his story to practice classifying and diagramming infinitives and review our seven sentence patterns at the same time.

Elizabeth’s brutal hand in killing Edmund no doubt sparked fear in the underground Catholic Club, as the Catholic leaders in England were called, but Edmund’s courage in the face of death did much to overcome that. Many were so inspired by Edmund that they, too, ended up offering their lives rather than compromising their souls.

Such is the way of martyrdom. Like the famous Christian author and historian Tertullian said during the early Roman persecutions, “The more they cut us down, the more we grow. The blood of the martyrs is the seed of the Church.” It would take several decades, but Catholicism would eventually be legalized again in England. Elizabeth would have little imagined how much it had thrived in the meantime.