Choosing Between Infinitive and Gerund: “To do” or “doing”?




My doctor asked me to try to avoid eating  greasy food
  main verb infinitive infinitive gerund  

The sentence above illustrates the use of infinitives and gerunds, but do you know why it is grammatically correct to use “to avoid” and not “avoiding”? This handout will help you make the right choice. 

Infinitives and gerunds are verb forms (neither of them can be a main verb), which can have several positions and functions in a sentence:








to do


Functioning as a subject

To speak three languages is hard.

– used in more formal registers

Speaking three languages is hard.

– used in formal and informal registers.

To show purpose or reason

To achieve their goals, the officials hired a new manager.

– used as a reduction of in order to

Following verbs1

The study intends to expand the research on the topic.


He discussed going to Washington, DC, with his colleague.

Following verbs with no change in meaning

It started to rain.

It started raining.

+ begin, continue, prefer, propose

Following verbs with a change in meaning

The participant stopped to smoke.

Meaning: The participant stopped in order to smoke.

The participant stopped smoking.

Meaning: The participant does not smoke any more.

+ remember, forget, go on, quit, regret, remember, try2

Following prepositions

Thank you for letting me know.


1 Infinitives and gerunds follow certain verbs and phrases, and there is no rule or reason why, for example, a verb attempt is followed by an infinitive (The paper attempts to address), but not a gerund (*The paper attempts addressing). This is simply a matter of memorization.

2 See to explore how these words differ in meaning when followed by an infinitive and gerund

Information above adapted from Folse, K. S. (2009). Keys to teaching grammar to English language learners: A practical handbook. Ann Arbor: University of Michigan Press.


To check whether a certain word is followed by a gerund, infinitive, or any other grammatical constructions:

- check the word in a learner’s dictionary (e.g. )

- use a collocation dictionary (e.g. )

- simply type the word in a search engine (e.g. Google) and examine the sentences that contain the word.


Identify whether an infinitive or gerund should be used in the sentences, underlining the correct forms. Explain your choice.

From Lesson Reflection – Class on Cloud Types

During the conclusion of the main lesson, students were asked to identify/identifying the cloud-type depicted in a fourth projection and to explain/explaining why they reached their particular conclusion. This would achieve learning goal three by to allow/allowing students to apply/applying what they learned about cloud types as evidence during a formal assessment. Students were allowed to use/using the information recorded on their worksheets and resources around the room to reach/reaching a conclusion. Students one, two, and three reached the conclusion that a cumulus cloud was shown on the projector, which is correct. However, only student one listed a reason for her answer by to write/writing the word “puffy”. So, despite to list/listing “cumulus” as their answer, most students failed to identify/identifying a reason for their response. From this evidence, I would conclude that students have learned how to apply/applying observations to formulate/formulating answers, but have not learned how to explain/explaining their answers through use/using evidence. Such limited explanations could also be due in part to a lack of emphasis on this task and a limited capacity to put thoughts into words.

Practice passage adapted from Michigan Corpus of Upper-level Student Papers. (2009). Ann Arbor, MI: The Regents of the University of Michigan. 

Last updated 9/1/2017