beware PREPOSITION

Writers often wonder: is it "interested in", "interested on", or "interested to"? The safe default for curiosity, desire, or ongoing interest is interested in + noun or interested in + -ing. Use interested to + infinitive for a reaction (I was interested to learn...). Avoid interested on, interested at, and usually interested about.

Quick answer

Use interested in + noun or interested in + -ing for ongoing interest (I'm interested in the position / in applying). Use interested to + infinitive to report a reaction (I was interested to learn...). Don't use interested on or interested at; prefer interested in instead of interested about.

Default: interested in + noun / gerund → I'm interested in marketing; She's interested in joining.
Reaction: interested to + verb → I was interested to hear the results.
Avoid: interested on / interested at / interested about when you mean 'curious about' or 'willing to do'.

Core explanation

Interested is an adjective that normally pairs with the preposition in to link to what you care about. After a preposition you need a noun or a gerund (verb+ing). A separate pattern-interested to + infinitive-reports that something struck you as notable.

Standard: interested in + noun or interested in + -ing (ongoing interest or desire).
Limited: interested to + infinitive (reaction: I was interested to learn...).
Avoid: interested on / at / about for meanings like 'curious about' or 'willing to do'.

Real usage: copy-ready sentences for work, school, and casual contexts

Short examples you can paste into emails, applications, or casual messages. Right-hand sentences use the recommended preposition and tone.

Work: I'm interested in scheduling a demo next Tuesday.
Work: We're interested in hearing your feedback on the draft.
Work: I'm interested in applying for the senior analyst role.
School: She's interested in joining the honors program next year.
School: I'm interested in researching renewable energy policy.
School: He's interested in studying cognitive psychology this semester.
Casual: I'm interested in checking out that new café.
Casual: She's interested in the new series everyone is talking about.
Casual alternative: I'm really into hiking lately (more informal).

Common wrong prepositions and why they fail

People transfer prepositions from other adjectives (keen on, good at, worried about) to interested, which creates errors. Remember which prepositions belong with which adjectives.

interested on → incorrect (confused with keen on)
interested at → almost always ungrammatical
interested about → nonstandard; prefer interested in or curious about

Wrong: She's interested on attending the meeting.
Right: She's interested in attending the meeting.
Wrong: Are you interested about the new policy?
Right: Are you interested in the new policy?

Examples bank - wrong → right pairs

Many common mistakes and their fixes. Copy the corrected sentence when you edit.

Wrong (work): I am interested on scheduling a demo next week.
Right (work): I am interested in scheduling a demo next week.
Wrong (work): We're interested at hearing your feedback.
Right (work): We're interested in hearing your feedback.
Wrong (work): She's interested to collaborate on the report. (clumsy)
Better (work): She's interested in collaborating on the report.
Wrong (school): I'm interested on researching climate adaptation.
Right (school): I'm interested in researching climate adaptation.
Wrong (school): He's interested about joining the honors program.
Right (school): He's interested in joining the honors program.
Wrong (school): I was interested to learn about the theory. (awkward for ongoing interest)
Better (school): I'm interested in learning more about the theory.
Wrong (casual): I'm interested on going out tonight.
Right (casual): I'm interested in going out tonight.
Wrong (casual): She's interested about the new show.
Right (casual): She's interested in the new show.
Wrong (casual): I'm interested to try that restaurant. (not wrong but less natural)
Natural (casual): I'd be interested in trying that restaurant.
Wrong (email): Interested on attending the webinar?
Right (email): Are you interested in attending the webinar?

Rewrite help: fast checks and copy-ready fixes

Quick checks to repair sentences and swap incorrect prepositions for correct patterns.

Check 1: Is the word after interested a noun or an -ing form? If yes, use in.
Check 2: If you wrote on/at/about, change it to in and check tone.
Check 3: If you meant 'that surprised me' or 'it was notable', use interested to + verb (usually past tense).

Rewrite:
Wrong: I am interested on applying for the role. → I am interested in applying for the role.
Rewrite:
Wrong: Interested to join? → Are you interested in joining?
Rewrite:
Wrong: I was interested about the results. → I was interested to learn the results. (or) I was interested in the results.
Rewrite:
Wrong: We're interested on your input. → We're interested in your input. (
Alternative: We would welcome your input.)
Rewrite:
Wrong: She's interested to lead the project. → She's interested in leading the project.
Rewrite:
Wrong: Interested at volunteering? → Are you interested in volunteering?

Try your own sentence

Check the whole sentence, not just the phrase. Context usually clarifies the right preposition.

Memory tricks to lock in "interested in"

Simple mnemonics help you avoid swapping prepositions.

Think "involved" - if you want to be involved, you go in (interested in).
Swap with curious: I'm curious about → I'm interested in.
Note the contrast: keen on uses on; interested does not. Keep them separate.

Example mnemonic: I'm interested in (involved in) volunteer work.
Swap test: I'm curious about the course → I'm interested in the course.

Similar mistakes to check while fixing prepositions

Fixing interested in often uncovers other collocation or verb-form errors. Handle them together.

interested vs interesting: interested = feeling; interesting = causing interest. Wrong: The lecture was interested.
Right: The lecture was interesting.
Verbs with fixed prepositions: apologize to vs apologize for; look forward to + -ing; be good at + noun.
Don't use infinitives after prepositions: incorrect: interested in to apply →
correct: interested in applying.

Wrong: The lecture was very interested.
Right: The lecture was very interesting.
Usage: Incorrect: I'm interested in to join. →
Correct: I'm interested in joining.

Spacing, hyphenation and short grammar notes

Write interested in as two words with normal spacing. Hyphens appear only in compounds that require them (self-interested).

Correct spacing: interested in learning (no hyphen).
Hyphen only in compounds: a self-interested choice.
Form: use gerunds after prepositions - interested in applying, not interested in to apply.

Wrong: I'm interested in to learn more. →
Right: I'm interested in learning more.
Hyphen example: a self-interested decision (hyphen with self- prefix).

Grammar: why gerunds after prepositions and when "to" appears

Prepositions require objects; verbs become objects when they turn into gerunds (verb+ing). That is why interested in + gerund is grammatical. Interested to + infinitive is idiomatic and reports a reaction to information.

After prepositions use nouns or gerunds: interested in joining, interested in the project.
Interested to + infinitive = reaction: I was interested to hear that the deadline moved.
Ongoing desire → use interested in + -ing; reporting reaction → interested to + verb.

Gerund example: She is interested in joining the lab.
To-infinitive reaction: I was interested to discover that the deadline moved earlier.

FAQ

Is "interested on" correct?

No. For 'curious about' or 'willing to do', use interested in + noun/gerund. Example: Incorrect: I'm interested on volunteering. Correct: I'm interested in volunteering.

Can I use "interested to"?

Yes, to report a reaction: I was interested to learn that... It doesn't replace interested in for ongoing interest.

Which is better: "interested in learning" or "interested to learn"?

Use interested in learning for ongoing desire or plans. Use interested to learn when something you heard or saw caused interest (a reaction).

Quick fix for "I am interested on applying"?

Change on to in: I am interested in applying. Or use an alternative: I'd like to apply / I'm keen to apply.

Easy way to remember the right preposition?

Link interested to involved - if you want to be involved, you go in. When in doubt, use interested in + -ing as the safe default.

Want a quick sentence check?

Paste a sentence into the widget above or compare it to the rewrite examples. Small fixes (interested in vs interested on) make messages clearer and more professional.