Grammar guide Updated 2026-10-06

Interested or Interesting? Teaching -ed and -ing Adjectives

An -ing adjective describes the thing that causes a feeling; an -ed adjective describes the person or thing that feels it. A film is boring and the audience is bored. The rule holds most of the time, and the useful lesson is in the places where it looks like it should not.

The one-line rule

Ask one question about the noun: does it cause the feeling or receive it? The cause takes -ing, the receiver takes -ed. A surprising result makes people surprised; a tiring week leaves people tired.

The common shortcut — people take -ed, things take -ing — breaks as soon as you meet a boring person, a frightened look or an exciting city. Teach the question, not the shortcut.

Twelve pairs worth drilling

Run the table twice: once reading the left column aloud and asking for the matching feeling, once reading the right column and asking what caused it.

Spelling both forms

Most pairs are one verb with two endings, so the spelling rules are the familiar ones from the present participle and the past simple.

• Drop a final e: bore becomes boring and bored; surprise becomes surprising and surprised.
• Double after a short stressed syllable: run becomes running, stop becomes stopping and stopped. But limit becomes limiting and limited, and visit becomes visiting and visited, because the stress is not on the last syllable.
• A consonant plus y changes to i: worry becomes worried and worrying; satisfy becomes satisfied and satisfying. A vowel plus y keeps the y: play becomes played and playing.

Two related pages cover the wider patterns: the adjectives vs adverbs guide works on what a describing word points at, and the gerunds vs infinitives guide shows the other job that -ing does in a sentence.

A three-question test for students

1. Find the noun. Which word are we describing?
2. Is it the cause or the receiver? If the noun creates the feeling in someone else, use -ing. If the noun has the feeling, use -ed.
3. Check with by or with a second sentence. I was bored by the film works; The film was bored by me does not. The one that takes the passive partner is the -ed form.

Prepositions that come with the pair

Each adjective carries its own preposition: interested in, excited about, worried about, satisfied with, disappointed with or in, surprised at or by, bored with or by, and tired of or from. Drill the preposition with the adjective, never separately.

Errors and the ambiguity behind them

• I'm boring for I'm bored. The first says you put other people to sleep. Ask students to test it on a classmate.
• a tiring day and I'm tired. The day is the cause; the person is the receiver. Both sentences are correct, which is why the pair must be taught together.
• The wrong -ed on a thing. The film was bored fails, because a film does not feel anything.
• feel plus a form. I feel tired describes a state; keep -ed with the person after feel.

Adjective or participle phrase?

In a boring lecture, boring is an adjective in front of a noun and simply names a quality. In the lecture boring everyone in the room, boring is a participle with its own object, doing the work of a clause that has been shortened: the lecture that was boring everyone. The -ed participle works the same way in the passive: the students bored by the topic means the topic acted on the students. Reduced relatives keep the same endings, so the children who were bored becomes the bored children. The relative clauses guide covers the full form these phrases come from.

Drill 1: mime and label

One student mimes a feeling; the class produces two sentences, one for each form. You're excited about something. Something was exciting. Pairs earn a point only when both forms arrive.

Drill 2: correction race

Give each pair eight sentences with one wrong form each: The lesson was bored. I was interesting in the topic. He is tiring after work. Pairs correct the form, then say which noun receives the feeling.

Drill 3: How did you feel? What was it like?

Students interview three classmates with two questions: How did you feel at the weekend? and What was it like? The first answer uses -ed; the second uses -ing. The grid fills with pairs of sentences, and the class sorts them at the end. The same round-and-report shape runs through the classroom grammar drills page.

Frequently asked questions

What is the difference between interested and interesting?

Interesting describes what causes the feeling: The talk was interesting. Interested describes who feels it: I was interested in it.

Do people always take -ed and things always take -ing?

No. A boring person is boring because they cause boredom in others, and an exciting city causes excitement. The question is not whether the noun is a person but whether it causes the feeling or receives it.

Which preposition follows interested and excited?

Interested takes in: interested in history. Excited takes about: excited about the trip. Worried also takes about, satisfied takes with, and disappointed takes with or in.

What is the difference between I'm boring and I'm bored?

I'm bored means I feel boredom. I'm boring means I cause boredom in other people, which is rarely the intended message. The same trap appears with tiring and tired, and with confusing and confused.

How is a boring lecture different from a lecture boring everyone?

Boring in a boring lecture is an adjective describing the noun. In the lecture boring everyone, boring is a participle with its own object, so the phrase is closer to a clause: the lecture that was boring everyone.

Keep reading

• Adjectives vs Adverbs: How to Teach the Difference
• Gerunds vs Infinitives: How to Choose
• Relative Clauses: How to Teach Who, Which and That
• Comparatives and Superlatives: A Teaching Guide