Prepositions with Infinitives and “to”: Structure and Usage Help

Mastering the use of prepositions with the infinitive form of verbs is a common challenge for English learners, as the rules can seem inconsistent and exceptions are frequent. For example, some verbs are directly followed by the infinitive, such as "want to go," while others require a different structure, like "interested in going." Recognizing these patterns and practicing them in context is crucial for achieving clear and accurate communication. Consistent exposure and usage help learners internalize these combinations and avoid common mistakes.

Where infinitives appear after prepositions in English

English learners often wonder if it’s ever correct to use an infinitive—such as “to go” or “to see”—directly after a preposition (words like “in,” “on,” “about,” “after”). In most standard English usage, infinitives do not directly follow prepositions. Instead, the “-ing” form (gerund) is preferred after prepositions. For example, we say “after eating” rather than “after to eat.” However, there are notable exceptions and nuanced uses involving certain expressions or fixed phrases.

General Rule: Prepositions + Gerunds, Not Infinitives

When a preposition comes before a verb, that verb will almost always be in the “-ing” form. Here are some common examples:

• She is interested in learning Spanish. ✅
• He apologized for being late. ✅
• They left without saying goodbye. ✅

Trying to use an infinitive in these contexts is incorrect:

• She is interested in to learn Spanish. ❌
• He apologized for to be late. ❌
• They left without to say goodbye. ❌

Apparent Exceptions: Fixed Phrases and “To” as a Preposition

Sometimes, “to” acts as a preposition, and it is followed by a noun or gerund, not an infinitive. Consider these cases:

• Look forward to meeting you.
• Be committed to improving quality.
• She’s used to working late.
• They’re opposed to raising taxes.

Here, “to” is part of the prepositional phrase, not the infinitive marker.

When Infinitives Do Follow Prepositions: Rare and Special Cases

There are a few rare situations where an infinitive might appear after a preposition, but these are almost always set expressions or older forms. In modern English, these are extremely limited. For example, “except” and “but” can sometimes be followed by a bare infinitive (without “to”), especially in literary or formal contexts:

• He did nothing but complain.
• She had no choice but to leave.

Notice that after “but,” both the bare infinitive and “to” + infinitive can sometimes be found, though the structure is idiomatic and should be learned case by case.

Comparison Table: Prepositions and Verb Forms

Useful Patterns and Common Mistakes

To help you remember which form to use, here’s a list of common prepositions and phrases that should be followed by a gerund, not an infinitive:

• before going → Think carefully before going to bed.
• after finishing → After finishing the lesson, take a short break.
• by doing → You can learn faster by doing small exercises daily.
• without knowing → He signed the form without knowing the full details.
• instead of leaving → Instead of leaving early, she stayed to help.
• in addition to studying → In addition to studying grammar, read short articles.
• be used to waiting → I’m used to waiting for the bus in the morning.
• look forward to seeing → I look forward to seeing you next week.
• be interested in learning → She’s interested in learning business English.
• be capable of winning → This team is capable of winning the final.
• be afraid of flying → He is afraid of flying alone.
• be tired of working → She’s tired of working late every night.
• be responsible for organizing → He is responsible for organizing the event.
• be excited about traveling → We’re excited about traveling together.
• be worried about making mistakes → Don’t be worried about making mistakes.
• be opposed to changing plans → They are opposed to changing plans at the last minute.

In summary, English overwhelmingly prefers the “-ing” form after prepositions, with only a few idiomatic exceptions where an infinitive appears. Recognizing these patterns will help you avoid common errors and sound more natural in your writing and speech.

Verbs and adjectives that take preposition + to + verb

Many English verbs and adjectives require a preposition followed by the infinitive form (“to” + base verb). This structure is common with phrases expressing willingness, readiness, reluctance, or obligation, as well as with certain reporting verbs and adjectives. Understanding which words use this pattern helps you sound more natural and avoid mistakes.

Common verbs and adjectives that use preposition + to + infinitive

Some words are almost always followed by a preposition and then an infinitive. Here are frequent ones:

• Look forward to: I look forward to meeting you. (Note: “to” is a preposition here, so use the -ing form, not the infinitive.)
• Be committed to: She is committed to helping others.
• Be opposed to: They are opposed to changing the rules.
• Be used to: He is used to getting up early.
• Be accustomed to: We are accustomed to working late.
• In addition to: In addition to studying, she works part-time.
• Object to: I object to being treated unfairly.
• Be dedicated to: The team is dedicated to improving performance.
• Be addicted to: He’s addicted to playing video games.
• Be related to: This issue is related to solving the main problem.
• Be opposed to: She’s opposed to raising taxes.
• Be open to: I am open to trying new things.
• Be limited to: The offer is limited to new customers.

Note: -ing form after preposition “to”

Although “to” is often associated with the infinitive, after certain verbs and adjectives with “to” as a preposition, the following verb is in the -ing form (gerund), not the base infinitive. This is a common source of confusion.

When “to” is part of the infinitive

Some verbs and adjectives use a different pattern: a preposition (not “to”) + “to” + base verb. Here, “to” is the infinitive marker. Examples include:

• Be ready to: She is ready to start.
• Be willing to: He is willing to help.
• Be reluctant to: They are reluctant to leave.
• Be eager to: I am eager to learn.
• Be afraid to: She’s afraid to ask.
• Be prepared to: We are prepared to wait.
• Plead with (someone) to: He pleaded with her to stay.
• Agree to: They agreed to meet.
• Refuse to: She refused to listen.
• Promise to: I promise to call.
• Offer to: He offered to help.
• Plan to: We plan to travel.

Quick comparison: “to” as preposition vs. “to” as part of infinitive

Mastering these structures takes practice. Pay attention to whether “to” is a preposition (followed by -ing) or the infinitive marker (followed by base verb). This will help you choose the right verb form and avoid common errors.

Meaning differences between to + verb and preposition + verb

Understanding how “to” functions before a verb versus how prepositions work with verbs can clarify many confusing English sentences. When “to” is used as part of the infinitive (to + base verb), it often expresses purpose, intention, or a possible action. In contrast, when a preposition comes before a verb, the verb must be in the -ing form, and the preposition usually links the verb to a noun, pronoun, or another verb, often indicating time, place, or manner.

“To” as an infinitive marker

Using “to” plus a verb (the infinitive) suggests intent, desire, or potential. It answers questions like “Why?” or “What for?” and is not tied to time or location.

• I want to eat. (expresses desire)
• She went there to study. (shows purpose)
• It’s important to listen. (states importance)

Prepositions before verbs

When a preposition comes before a verb, the verb changes to its -ing form (gerund). This structure typically links the action to another element in the sentence, emphasizing relationships like cause, method, or time.

• He’s interested in learning French. (interest in an activity)
• They talked about going abroad. (topic of conversation)
• She apologized for being late. (reason for apology)

Common meaning contrasts

The difference in meaning can be subtle but important. Below is a comparison of typical patterns:

Quick reference: verbs with prepositions vs. infinitives

Some verbs are commonly followed by a preposition + -ing, while others take the infinitive. Here are examples to illustrate the patterns:

• look forward to meeting you (preposition “to” + -ing)
• decide to leave (infinitive)
• insist on doing something
• plan to travel
• apologize for missing the meeting
• agree to help
• worry about failing
• offer to assist
• think about moving
• promise to return
• be interested in learning
• need to finish
• be responsible for organizing
• hope to see
• be afraid of flying
• try to win
• be tired of waiting
• forget to call

By recognizing these structures, you can better choose the right form for clarity and precision in your writing and speech.

Avoiding double to and redundant prepositions

When working with infinitives and prepositions, it’s easy to accidentally repeat “to” or stack unnecessary prepositions. These mistakes can make sentences awkward or unclear. Understanding which combinations are redundant will help keep your writing and speech more natural and concise.

Common Double “To” Errors

Sometimes, learners add an extra “to” before an infinitive, especially after verbs or prepositions that already imply direction or purpose. Watch out for these patterns:

• I want to go. ✅
• I want to to go. ❌
• She agreed to help. ✅
• She agreed to to help. ❌

The rule: Use only one “to” before the infinitive.

Redundant Prepositions Before Infinitives

Certain verbs and adjectives require prepositions, but when followed by an infinitive, adding another preposition is usually unnecessary—and sometimes ungrammatical. For example:

• He is afraid to speak. (not afraid of to speak)
• They decided to leave. (not decided on to leave)
• She prepared to run. (not prepared for to run)

If you’re unsure, try the sentence without the extra preposition. If it still makes sense, the preposition is probably unnecessary.

Typical Redundant Patterns to Avoid

Many common phrases tempt learners to insert an extra “to” or preposition. Here are examples to keep in mind:

• Try to understand (not try for to understand) → Try to understand the main idea first.
• Promise to call (not promise for to call) → He promised to call me later.
• Plan to travel (not plan on to travel) → They plan to travel abroad next year.
• Offer to help (not offer for to help) → She offered to help with the project.
• Refuse to participate (not refuse from to participate) → He refused to participate in the discussion.
• Learn to swim (not learn at to swim) → Children learn to swim at a young age.
• Agree to meet (not agree on to meet) → We agreed to meet after work.
• Ask to join (not ask for to join) → She asked to join the team.
• Help to solve (not help with to solve) → This guide will help to solve common problems.
• Fail to notice (not fail in to notice) → I failed to notice the warning sign.
• Manage to finish (not manage with to finish) → He managed to finish the report on time.
• Wish to see (not wish for to see) → I wish to see that place one day.
• Hope to win (not hope for to win) → They hope to win the championship.
• Need to leave (not need for to leave) → I need to leave early today.
• Decide to start (not decide about to start) → She decided to start her own business.
• Want to learn (not want for to learn) → I want to learn English fluently.
• Seem to know (not seem like to know) → He seems to know the answer.

Quick Reference: Correct vs. Incorrect Structures

Reviewing these patterns will help you avoid unnecessary repetition and keep your use of infinitives with prepositions accurate and streamlined. When in doubt, read your sentence aloud—if it sounds clumsy or repetitive, you may have doubled up where you don’t need to.

Patterns common in formal and academic writing

Writers in academic and professional settings often follow established conventions when combining prepositions with infinitives, especially when using “to.” These combinations contribute to clarity and precision, ensuring the intended meaning is easily understood by readers accustomed to formal prose. Certain structures appear far more frequently in research papers, essays, and reports than in everyday conversation.

Typical preposition + infinitive structures

Some pairings of prepositions and infinitives are especially characteristic of scholarly communication. Here are several common patterns:

• In order to + verb (e.g., In order to demonstrate the results, …)
• So as to + verb (e.g., The sample was heated so as to accelerate the reaction.)
• With a view to + verb-ing (e.g., The study was conducted with a view to improving efficiency.)
• For the purpose of + verb-ing (e.g., Data were collected for the purpose of analyzing trends.)
• Be about to + verb (e.g., The experiment is about to begin.)
• Be likely/unlikely to + verb (e.g., The method is likely to produce accurate results.)
• Be required/expected/allowed to + verb (e.g., Participants were required to sign a consent form.)
• Be prepared to + verb (e.g., Students should be prepared to discuss their findings.)
• Be intended to + verb (e.g., This section is intended to clarify the methodology.)
• Be necessary to + verb (e.g., It is necessary to examine the data closely.)
• Be sufficient to + verb (e.g., The evidence is sufficient to support the hypothesis.)
• Be able/unable to + verb (e.g., The device is able to detect small changes.)
• Be obliged to + verb (e.g., Researchers are obliged to follow ethical guidelines.)
• Be permitted to + verb (e.g., Students are permitted to use calculators during the test.)
• Be encouraged to + verb (e.g., Authors are encouraged to submit original work.)
• Be designed to + verb (e.g., The survey was designed to gather qualitative data.)

Formal alternatives to everyday expressions

Writers aiming for a more scholarly tone often prefer certain phrases over their informal counterparts. For example, “in order to” is favored over simply “to” when explaining purpose, and “so as to” is more formal than “so that.” These choices add precision and formality to academic texts.

Common errors and corrections

Using the wrong preposition or omitting necessary elements can lead to ambiguity. For instance, “with a view to” should be followed by a gerund, not an infinitive. On the other hand, “in order to” correctly takes the base form of the verb. Here is a comparison of correct and incorrect forms:

Usage tips

Pay close attention to the required verb form after each prepositional phrase. Not all prepositions are followed directly by an infinitive; some require a gerund, especially in more elaborate constructions. In research writing, erring on the side of formality and consistency helps maintain credibility and reader trust.

Practice: rewrite sentences with correct infinitive structures

Understanding how prepositions interact with infinitives can be tricky. Here you’ll work with sentences that contain common mistakes related to infinitive usage, especially after prepositions and “to.” Your task: rewrite each sentence so it uses the correct structure—whether that means adding, removing, or moving “to,” or switching from an infinitive to a gerund. These examples focus on real-world errors learners often make.

Rewrite these sentences for correct infinitive use

1. She is interested to learn French.
2. He apologized to arrive late.
3. You need to focus on to improve your writing.
4. They decided on to take the earlier train.
5. I look forward to see you soon.
6. We talked about to start a new project.
7. She insisted on to pay for dinner.
8. He is good at to draw animals.
9. She suggested to go to the museum.
10. He promised of to help me tomorrow.
11. They are worried about to lose the game.
12. I am used to wake up early.
13. He’s responsible for to organize the event.
14. They plan on to move next year.
15. I agreed to help with cleaning.
16. She refused of to join us.
17. He hopes for to get a promotion.
18. I am thinking about to travel abroad.
19. She’s capable of to solve the problem.
20. He’s afraid of to speak in public.

Common patterns: Prepositions with gerunds vs. infinitives

Some verbs and expressions are always followed by gerunds after prepositions (like “interested in,” “good at,” “responsible for”), while others take infinitives without a preceding preposition. See the overview below for reference:

• After prepositions: use the gerund form (-ing): “She’s good at singing.”
• After certain verbs: use the infinitive: “He wants to leave.”
• After “to” as a preposition (e.g., “look forward to”): use the gerund: “I look forward to meeting you.”
• After “to” as part of an infinitive: use the base verb: “I hope to see you.”

Reviewing and practicing these distinctions helps avoid common pitfalls with infinitive and gerund structures in English.