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Lesson: To Infinitives and Beyond!

Infinitive Lesson Plan

Infinitives aren’t really attention-getters in a world where the glory usually goes to adjectives, nouns, adverbs, pronouns, and conjunctions. Don’t underestimate these parts of speech. They may seem small, but they’re mighty. Infinitives aren’t just important; they’re also fiercely independent. They are the basic form of a verb without inflection that are not bound to any particular subject or tense. For example “eat” functions as an infinitive in the following sentences:

  • We went inside to eat.
  • Let her eat.

Webpage to Discuss in Class: Infinitive

EduFind is a website that teaches many of the basic building blocks of English grammar. A handy feature of this site is its assessment tools. There’s a basic grammar test as well as a link to a much more intense 2-hour test which is quite similar to TOEFL and IELTS.

For now, we’ll focus on EduFind’s infinitives section. On this page, the reader learns that there are two main forms in which infinitives will usually exist. These forms are the “to infinitive” and the “zero infinitive”.  As one might guess, to infinitives are seen in phrases such as “to swim”, “to sleep”, and “to think”. The zero infinitive occurs when the verb is left on its own, without the “to”. Therefore, sleep, think, and swim are all zero infinitives.

When to infinitives are used to indicate the purpose or goal of an action, they exist as a shorter form of “in order to”. For example:

 Eddie went to the medical supply store to buy a knee brace.

A to infinitive can also operate as a sentence’s subject, but this happens much more frequently in written English than it does in spoken English. Here’s an illustration of this point:

To eat at Arby’s is my plan for tonight.

A to infinitive may also follow an adjective. When it does, the following formula is typically used (supplied by EduFind):

Subject + “to be” + adjective + “for/of” someone + to infinitive + rest of sentence.

We see this formula in the following sentence:

It is important for Jane to be cautious when running.

Let’s take a look at how the formula was employed.

It = subject

 is = to be

important = adjective 

for Jane = for/of someone 

to be = to infinitive

cautious when running = rest of sentence

To infinitives can also be used to express an opinion or to make a judgment.  For example:

That was a stupid thing to do.

In this sentence, as is the general rule, the to infinitive follows the noun phrase when making a judgment or stating an opinion.

To infinitives also are useful in sentences containing question words. As EduFind points out, question words often involve the 5 Ws (and one H), which are who, what, when, where, why, and how. Here are two examples:

Jimmy asked me how to start the lawn mower.

Donald asked Diane when to open the door.

Zero infinitives also have their time and place. They can be used after words of perception, which is another way of saying verbs involving the five senses. Here’s one example of this:

We heard them yell.

I saw it.

As you can see, there is no “to” in these sentences, making the infinitives used zero infinitives.

Zero infinitives can also be used after the words “make” and “let”.

Jerry’s brother let him use his hammer.

I can’t make you do your homework.

You’ll also see zero infinitives in sentences that use the expression “had better”.

You had better arrive on time.


Webpage to Discuss in Class: What are Auxiliary Verbs?

EC English is a valuable resource both for native English speakers and ESL learners. It is a multimedia English language learning website that contains text, audio, and video content. It presents many lessons in a blog format. Its lessons are so plentiful and frequently updated that the site boasts “a lesson a day”.

On its page concerning the definition and use of auxiliaries, we learn that they are words that act as “helpers”. They aid in creating sentences that run smoothly and are grammatically correct. EC English tells its readers that some of the most commonly seen auxiliaries are be, have, do, could, should, would, must, might, may, and can.

Take a look some auxiliaries in action along with zero infinitives in the following examples.

  • He can work today.
  • I must sleep more.
  • Would you like some?
  • Tom might agree.

These auxiliaries are often a part of the picture when infinitives are used in the passive voice. Typically, this is done when conveying that something is either accurate or could potentially happen. We’ll illustrate this for you with the examples below.

  • Mark should be given some.
  • I may be eligible to join.

Infinitive Video Resources

  1. English Grammar – 5 Ways to Use Infinitives

Source: English Lessons with Alex

Run Time: 6:00

Grade Level: 9-12

Description: This video defines infinitives in a basic context. It displays ways in which infinitives can be sentence objects, sentence subjects, subject complements, adjectives, and adverbs.


  1. Gerund or Infinitive?

Source: English Lessons 4 U

Run Time: 6:05

Grade Level: 6-8

Description: This video helps to clear up the sometimes foggy boundary between gerunds and infinitives. It also helps to dispel the myth that one can never split an infinitive.


  1. Infinitive Forms

Source: Mexus Education

Run Time: 10:34

Grade Level: 9-12

Description: This video is presented in the form of a cartoon. In it, a grandmother speaks with her three grandchildren who are trying to decide what they want to do. In the process, she points out and explains the various tenses of infinitives, which include simple present, present continuous, present perfect, present perfect continuous, and passive.


Reinforcement Exercises


Middle School: Design a worksheet including sentences that use to infinitives and others featuring zero infinitives. Have your students circle the infinitives where they appear. Then, provide a space after the sentence for your students to write “T” if the sentence features a to infinitive or “Z” if it features a zero infinitive.


High School: Have your students write out 20 sentences containing both to and zero infinitives. Instruct your students to include at least once sentence each of where the infinitives either express purpose, act as a subject, follow an adjective, are used with an auxiliary, make a judgment, contain question words, and include the phrase “had better”.


If you have any good pronoun-focused infographics, worksheets or videos that you use in the classroom, please share in the comments.


By Scott Kalapos, Education World Contributor