One rule that constantly confuses English learners is why it is sometimes possible to use "to" with a verb in "ing" form, such as "to eating". While it is uncommon to use "to" with a gerund (-ing) form, there are some cases where it's not only correct but necessary.
The word “to” is confusing to many students because it is used in two different ways. Even though the word "to" looks the same in each case, it is a different type of word, either a participle or a preposition. When it is a preposition, a verb after it needs to become gerund (-ing) form.
Both of these cases will be explained below.
a) Particle - Part of an Infinitive Verb
The word “to” can be part of an infinitive verb, such as “to go”, “to sleep”, and “to eat”. In this case, the word “to” is called a particle, which means that if you want to create an infinitive verb, you need the particle “to”:
Infinitive Verb = Particle + Present Base Form Verb = To Go
This infinitive verb form (ex. “to go”) is used in many situations and is one of the five main ways we can write a verb in English (ex. go/went/to go/going/gone). You might recognize an infinitive verb from the following situations:
After certain verbs like “want”, “like”, and “decide”: “we decided to go to the beach.”
Describing a goal or purpose of an action: “I went to the store to buy some food.”
After nouns like “something”, “nothing”, and “anything”: “do you want something to eat?”
After adjectives like “nice”, “easy”, and “fun”: “it was nice to take a vacation for a week.”
The key point is that in each case above, the word “to” is married to the base form verb (go, buy, eat, take), which means they are always together as one “package”. Think of an infinitive verb like “to go” as one word instead of two separate words.
b) Preposition - Connects to a Noun
The purpose of a preposition in English is to add a noun that tells us when, where, why, or how something happens. A preposition always connects to a noun.
I go to school – the preposition “to” describes where I go (the direction of the school)
I did it for you – the preposition “for” describe why I did it (benefitting “you”)
I exercise in the morning – the preposition “in” describes when I exercise
I studied at the library – the preposition “at” describes where I studied
As you can see in the first example above, the word “to” is a preposition which describes direction. You might remember other situations when “to” describes a direction, either literally or figuratively:
He talked to me.
She listened to me.
He gave it to me.
They lied to me.
Did you send it to me?
Now you understand the difference between “to” as a particle to create an infinitive verb (“to eat”) and “to” as a preposition to connect to a noun (“to school”). Next it is important to understand that when "to" is a preposition, it cannot connect to a base form verb - it needs to connect to the gerund form of a verb, because a gerund is a noun and prepositions only connect to nouns.
Prepositions and Gerunds
It’s a very important rule of English to remember that a preposition only connects to nouns, and this means that when a word is a verb, such as “study”, it needs to change to a noun first before it can connect to a noun.
A gerund is the -ing form of a verb word, which is the noun form, so “study” as a gerund is “studying”, which means that “studying” is a noun. Therefore, because “studying” is a noun, we can add it to a preposition:
I am tired of studying for this test.
I am good at studying English.
I am interested in studying psychology.
In the examples above, the prepositions are quite obvious – of, at, and in. However, remember that “to” can also be a preposition, and when it is being used as a preposition, the verb must be changed to gerund form in the same way as “study” was changed to “studying” after each preposition above. In the example below, the word “to” is a preposition, so the verb “study” changes to the noun “studying”:
Young people are used to studying because they do it every day at school, so they are better at it than older people.
In the example above, the word “used” connects to the preposition “to” (be + used + to), so the verb “study” has to be in gerund form – “studying”.
At this point you might be wondering: “how do I know when ‘to’ is a preposition so that I use a gerund and when ‘to’ is a particle as part of an infinitive verb?”. This is a fair question but unfortunately the answer is not easy. It mostly requires memorizing the specific cases when “to” is a preposition. The good news is that there are not too many cases, and most of the common ones are provided below.
Words That Use “to” As a Preposition
Adapt to (sth): “I was able to adapt to living in another country more easily than I thought.”
Admit to (sth): “She admitted to stealing the money.”
Contribute to (sth): “The storm contributed to the ship sinking.”
Lead to (sth): “The coronavirus situation led to many countries closing their borders.”
Look forward to (sth): “I look forward to seeing you next week!”
Be addicted to (sth): “He is addicted to playing video games.”
Be related to (sth): “My job is related to helping people find jobs.”
Be used to (sth): “I am used to living alone. I have lived alone since I was 19 years old.”
With regard/respect to (sth): “With regard/respect to changing the event location, it has been decided that the new location will be the Hilton Hotel.”
In summary, remember that “to” (as a preposition) + a gerund is much less common than when “to” is part of an infinitive verb. For example, you will see “to do” much more often than “to doing”. However, it’s important to remember the list above so that you can remember that in these specific cases, the word “to” is a preposition, and therefore the verb after it needs to be changed into a gerund/noun form.
Practice For the exercises below, use the verb in the brackets to fill in the blank. If the part before the blank includes a word from the list above, such as “admit”, then the word “to” is a preposition so the verb should change to gerund form (ex. “he admitted to stealing the money”). However, some are tricks and do not use "ing". Only use "ing" form if it's a word from this lesson. The answers are given below the exercise.
If the part before the blank has a word that is not from the list above (ex. “decide”) then it connects to an infinitive verb (“he decided to quit his job").
1. He is addicted to smoking (play) ! – in this case, “to” is a preposition because of “addicted”
2. I want to travel (travel). – in this case, “to” is part of an infinitive verb “to travel” because of “want”
3. It took a few months, but I eventually adapted to ____________ (live) alone.
4. Everyone has to ___________ (sign) in when they enter the building.
5. I look forward to ______________ (see) you on Friday!
6. My friend asked me to _______________ (drive) him to the airport tomorrow.
7. It’s very hard to __________ (practice) a foreign language when you don’t live in that foreign country.
8. I wasn’t nervous when I spoke at my friend’s wedding. I am used to ___________ (speak) publicly.
9. Working from home is very convenient compared to ________________ (work) at an office.
10. I don’t know his job exactly, but I know it’s related to _______________ (give) financial advice.
11. My parents plan to _____________ (sell) their house soon.
12. The government’s decision led to people _______________(protest) in the streets.
13. Her new diet has contributed to her ________________ (lose) over twenty pounds.
14. His manager allowed him to __________________ (leave) the office early yesterday.
Answers
1. Playing
2. Travel
3. Living
4. Sign
5. Seeing
6. Drive
7. Practice
8. Speaking
9. Working
10. Giving
11. Sell
12. Protesting
13. Losing
14. Leave