Students often have a difficult time knowing when to use gerunds and infinitives.
Even at the intermediate level, this is typically not covered extensively and lesson plans instead focus on very specific structures such as “I like playing ~.” or “I like to play ~.”
For the majority of students this simple approach is enough and much less confusing than trying to understand when one is more appropriate than the other because in many situations, although there is a slight difference in meaning, gerunds and infinitives are used interchangeably. A lesson teaching gerunds might focus on “I like playing/eating/reading ~.” and the question “What do you like doing?” When students create sentences that are incorrect, for instance “I like playing ski.” you can address the fact that ski does not follow the same rules as sports such as soccer, baseball, and basketball. An introductory infinitive lesson could use the same approach in order to give students some easy infinitive practice without overwhelming them with various structures and uses. With more advanced students or if the difference between gerunds and infinitives is covered in your textbook, you will have to address them in more detail.
How to Proceed
Gerunds and Infinitives
Gerunds are nouns formed from verbs. Gerunds are formed by adding –ing to the end of a verb. Some examples are eating, playing, and listening. Infinitives use to before the verb so the examples above would be to eat, to play, and to listen. Both can be used as the subject or object of a sentence. The negative version of both gerunds and infinitives is made simply by adding not. With this information alone, you can create lesson plans that focus on the various uses of gerunds and infinitives and give students some practice using them in sentences. Certainly looking at how the two are similar is the easiest method of introducing the topic.
Gerunds can also be used in prepositional phrases like in the sentence “They talked about swimming yesterday but decided it was too cold.” Additionally there are certain words that should be followed by gerunds such as avoid, enjoy, and dislike and there is no great way to remember which words except through considerable amounts of practice using them. A mistake learners often make is saying a sentence similar to “I go to swim everyday.” when the correct sentence is “I go swimming everyday.” or even “I go to the gym to swim everyday.” When certain words, such as swim, follow the verb go, they must be gerunds. This applies to many activities such as swimming, scuba diving, skiing.
There are also some words such as demand, hope, and pretend, that must be followed by an infinitive. As with gerunds, it takes a lot of practice to recognize which words this applies to and there is no rule to help. Additionally, when the main verb of the sentence is a form of be followed by an adjective, an infinitive often follows. One example is “They were anxious to leave.” There are other structures that use infinitives as well. Trying to address all of them in a single class period will simply confuse students. It would be better to select what key points you want to cover or spread these lessons out over the course of the year so that students do not become bored studying just one aspect of the English language.
Once your students have had some practice using both gerunds and infinitives in separate lessons, combine them. You can give the class pairs of sentences where one sentence uses a gerund and the other uses the infinitive. Then as a class or in groups discuss the slight to substantial differences in meaning the sentences have. This is a challenging activity and should only be done with advanced students.
With any luck your textbook will not address gerunds and infinitives directly but will still give students lots of practice using them.
This method generally works best it is more similar to how native speakers learn English. It is hard to explain why “I go to swim everyday.” is incorrect while “I go to work everyday.” is correct. Native speakers never question that because they are introduced to words, phrases, and sentence structures gradually by listening to people around them. The best way for students to learn English is not to memorize rules and exceptions to rules but to hear sentences modeled correctly and practice them.