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TOEIC Link Part 5 — Participial Adjectives: interested vs interesting and the -ed/-ing Rule

Part 5 tests -ed and -ing participial adjectives (interested vs interesting, confused vs confusing) with one decisive question: does the noun FEEL the emotion or CAUSE it? This guide gives the source-versus-experiencer rule, the linking-verb slot check, the people-are-usually--ed heuristic, and worked items with the exact distractor logic TOEIC uses.

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The attendees were ____ by the length of the keynote. Is it bored or boring? Both are real adjectives, both fit the slot grammatically, and Part 5 offers you both — the entire item turns on a single semantic distinction. An -ed participial adjective describes the one who feels the emotion; an -ing participial adjective describes the thing that causes it. Decide which role the noun plays and the answer is forced.

The one rule: experiencer vs source

Every participial-adjective item reduces to this question:

Does the noun FEEL the emotion (-ed) or CAUSE the emotion (-ing)?

  • -ed = experiencer. The subject receives/feels the emotion: The audience was *bored*. (they felt boredom).
  • -ing = source/cause. The subject produces the emotion in someone else: The lecture was *boring*. (it caused boredom).

Apply it to the opening item: The attendees were ____ by the length — the attendees felt the emotion, so bored. Flip the sentence and the adjective flips: The length of the keynote was *boring* — now the length is the cause, so -ing.

The people-usually--ed heuristic (and its limit)

Because people are normally the ones who feel emotions, a fast first pass is:

  • People → usually -ed: interested, confused, satisfied, excited, disappointed.
  • Things / events / reports → usually -ing: interesting, confusing, satisfying, exciting, disappointing.

So a *satisfied* customer but a *satisfying* result; the *confused* new hire but the *confusing* instructions.

But this is a heuristic, not the rule — and TOEIC exploits the exception. A person can be the cause of an emotion in others: He is a *boring* speaker (he causes boredom in the audience), She is an *interesting* colleague (she causes interest). When the person is described as the source of an effect, use -ing even though the noun is human. Always fall back to the source-vs-experiencer test rather than the people--ed shortcut.

The slot is the same either way — so grammar won't decide it

Both forms are adjectives, so they occupy the identical slots, which is exactly why you cannot solve these on structure alone:

  • After a linking verb: The results were *encouraging*. / The team was *encouraged*.
  • Before a noun: an *encouraging* trend / the *encouraged* staff.

A by-phrase is the strongest clue: The staff were ____ *by the results* points to -ed (experiencer) because by introduces the cause, leaving the subject as the one affected. This mirrors the passive-voice logic where by marks the agent — here the "agent" is the emotional source.

Working an item end to end

Management found the quarterly figures ____ and asked the analysts to prepare a recovery plan. (A) alarming (B) alarmed (C) alarm (D) to alarm

  • Slot check: found [object] ____ needs an adjective describing the quarterly figures. Kill the noun/verb alarm (C) and the infinitive to alarm (D).
  • Source vs experiencer: the figures do not feel alarm — they cause alarm in management. Cause → -ing.
  • Answer: (A) alarming. The trap alarmed (B) would say the figures themselves felt alarm, which is impossible for an inanimate subject. Note the structure found X alarming — the adjective describes the object figures, not the subject management.

Reverse the roles and the answer reverses: Management was ____ by the quarterly figures → management feels it → alarmed.

The 10-second procedure

  1. Confirm both options are the -ed/-ing pair of the same word — if so, grammar won't decide it; go semantic.
  2. Ask: does this noun feel the emotion (-ed) or cause it (-ing)?
  3. Inanimate subject (report, result, news, situation) → almost always -ing.
  4. See a by-phrase naming the cause? The subject is the experiencer → -ed.
  5. Human noun described as a source of an effect → -ing despite being a person.

This is a pure meaning-driven item in a section that usually rewards structure, so it pairs well with the word-choice-versus-word-form triage for spotting which kind of question you're facing. For the broader adjective-versus-adverb decision that governs neighboring items, see the adjective and adverb confusable pairs guide, and for fitting these reflexes into a timed plan, our reading strategies by question type guide.