動名詞 vs 不定詞: 8 Rules Taiwan Pros Master (2026) | Gerund Infinitive 完整指南

Every Taiwan professional who has emailed a client “I look forward to meet you next week” has lost the same one-point grammar battle. The choice between 動名詞 (gerund / V-ing) and 不定詞 (infinitive / to V) is one of the most quietly punishing topics in English — small in scope, huge in frequency. It shows up in TOEIC Part 5, in cover letters, in meeting recaps, and in almost every business email you write.

This guide lays out the eight rules that cover roughly 95% of real-world cases for gerund and infinitive in English. The rules are mechanical. Memorise the patterns, run the verb-list tables, and the “to meet / meeting” coin-flip stops being a coin flip.

動名詞 (V-ing) 與不定詞 (to V) 是台灣學習者最常混用的兩種句型 — 規則其實很機械化。

What’s the Difference? 動名詞 vs 不定詞 一句話搞懂

A gerund (動名詞) is a verb wearing a noun’s clothing — you take any verb, add -ing, and treat it as a noun. Reading, swimming, negotiating. An infinitive (不定詞) is the form to + base verb: to read, to swim, to negotiate. Both can act as subjects, objects, or complements, but they are not interchangeable.

Here is the rough semantic split that linguists use, simplified:

• Gerund (V-ing) = the action viewed as a real, ongoing, or completed experience — facts, habits, things that already happened. 已發生 / 經驗 / 事實。
• Infinitive (to V) = the action viewed as a goal, a plan, or something not yet done — intention, purpose, future-leaning. 目標 / 計畫 / 未發生。

So I remember locking the door means you actually locked it. I remembered to lock the door means you had a plan and carried it out. Same verb, two different worlds. We come back to this trap in Rule 6.

The catch is that English speakers do not consciously think about this distinction — they just memorise which verbs take which form. That is exactly what Taiwan learners need to do. The rest of this article is the shortcut.

Rule 1: Use a Gerund as the Subject — Not an Infinitive | 動名詞當主詞

主詞位置幾乎都用動名詞 (V-ing)，不定詞放句首很罕見。 The subject slot almost always wants a gerund.

When the action is the subject of the sentence, modern English overwhelmingly prefers the gerund. Swimming is good for you sounds natural. To swim is good for you sounds like a sentence from 1880. Cambridge English corpus data backs this up: gerund subjects outnumber infinitive subjects roughly nine to one in spoken and written English alike.

The standard workaround for the infinitive is the dummy it pattern: It is + adjective + to + V. Compare:

• ❌ To learn English takes time. (grammatical, but stiff)
• ✅ Learning English takes time. (gerund subject — natural)
• ✅ It takes time to learn English. (dummy it + infinitive — also natural)

For Taiwan TOEIC test-takers, the rule of thumb is: see a verb at the start of a clause acting as the subject, choose V-ing.

Rule 2: After the Main Verb, Let the Verb Decide | 受詞位置由主動詞決定

主動詞會「決定」後面接 V-ing 還是 to V — 沒有規則，只有清單。 The main verb decides whether the following verb is V-ing or to V.

When a verb is followed by another verb, English forces a choice. I enjoy ___ ? I want ___ ? The verb in front decides which form comes next. Some verbs take only gerunds, some take only infinitives, some take both. There is no rule that predicts which is which — only lists to memorise.

This is the source of most Chinglish errors in Taiwan offices. Mandarin has no equivalent rule because the second verb in Chinese has no inflection (我喜歡游泳 / 我計畫游泳 — same verb form). When Taiwan learners port that flat structure into English, the result is sentences like “I look forward to meet you” instead of the correct “I look forward to meeting you.” The rest of this guide is the cheat sheet.

Rule 3: Verbs That Take ONLY a Gerund | 只能接動名詞的動詞

這些動詞後面 100% 接 V-ing — 沒有例外。 These verbs take V-ing 100% of the time — no exceptions.

The following high-frequency verbs are gerund-only. Put any of these in front of another verb and the second verb must be in V-ing form. Memorise this block — it appears in TOEIC Part 5 almost every test cycle.

Three more deserve a mention because Taiwan learners mishandle them weekly: discuss, quit, and miss. Discuss never takes about in English — you discuss something, not discuss about something. If you discuss doing something, it’s V-ing. The team discussed launching in Q3.

Rule 4: Verbs That Take ONLY an Infinitive | 只能接不定詞的動詞

計畫、決定、希望、目標 — 動詞語意偏「未來」的，通常接不定詞。 Plan, decide, hope, goal — verbs with a forward-looking feel usually take to V.

These verbs are infinitive-only. Notice how many of them imply intention or future action — that is the semantic glue holding the list together.

Notice the semantic family: want, plan, hope, expect, agree, offer, refuse, decide — every single one points to a possible future. That is the easiest mental anchor for the list. If you want to deepen your toolkit on this kind of structure, our guide to English modal verbs covers the related “modal + base verb” pattern (can / should / must + V) that Taiwan professionals often confuse with the to V form.

Rule 5: Verbs That Take Both — Meaning Stays the Same | 兩者皆可，意思相同

For a handful of common verbs, you can pick either form and the sentence means the same thing. Begin, start, like, love, hate, prefer, continue all fall into this bucket. Native speakers will not flag a difference if you write either.

• I love swimming in the morning. ✅
• I love to swim in the morning. ✅
• It started raining. ✅
• It started to rain. ✅

One small style note: in British English, love / hate / like + V-ing is more common for general preferences, and the infinitive is more common for specific occasions (I like to arrive ten minutes early). In TOEIC, both will be marked correct. Don’t lose sleep over the difference at this stage.

Rule 6: Verbs That Take Both — But the Meaning CHANGES | 意思完全不同的陷阱

同一個動詞，後面接 V-ing 或 to V，意思可能差到 180 度。 Same verb, different form, often the opposite meaning.

This is the rule that costs Taiwan TOEIC candidates the most points. A small set of verbs takes both forms but means something different depending on which form follows. Get this wrong in an email and you accidentally say the opposite of what you intended.

The single highest-impact pair on this list for Taiwan workplaces is remember / forget. If your boss says “Remember to send the report,” she means do it now. If she says “I remember sending the report,” she means it’s already done. Mixing these two creates avoidable miscommunication in email threads — exactly the kind of thing reviewers downgrade you for. The same kind of meaning-shift trap shows up in our guide to English conditionals — small grammar tweaks, big swings in meaning.

Rule 7: After a Preposition, Always Use a Gerund | 介系詞後 100% 接動名詞

看到介系詞 (in, on, at, of, for, about, by, after, before…)，後面接動名詞，沒有例外。 See a preposition, write V-ing — every time.

If a verb follows a preposition, it is always in V-ing form. Always. No exceptions. This is the most absolute rule on the entire page and the easiest one to get right once you notice it.

• I am interested in learning Japanese. (not to learn)
• She is good at negotiating contracts.
• Thank you for sending the file.
• We talked about hiring a new designer.
• I look forward to meeting you. ⚠️

That last one is the most-failed example in Taiwan business emails. The “to” in “look forward to” is a preposition, not part of an infinitive. Other phrases with this same trick: be used to + V-ing (習慣於), get used to + V-ing, be accustomed to + V-ing, object to + V-ing, be opposed to + V-ing. Pattern-match on the structure, not on the word “to.”

If you want a deeper drill on which preposition pairs with which verb or adjective, our English prepositions guide for Taiwan professionals covers the in/on/at family and common collocations.

Rule 8: Common Gerund & Infinitive Mistakes Taiwan Learners Make | 台灣人最常犯的錯誤

這五個錯誤幾乎每個台灣商務英文學習者都犯過。 These five mistakes show up in almost every Taiwan business writing sample.

After grading thousands of TOEIC writing samples and business emails in Taiwan over the years, the same five errors keep surfacing. Fix these and your written English will jump a full band overnight.

1. “Look forward to meet you.” ❌ → “Look forward to meeting you.” ✅ — to is a preposition here. (Rule 7)
2. “I’m used to drink tea.” ❌ → “I’m used to drinking tea.” ✅ — habit, preposition + V-ing.
3. “She suggested to leave early.” ❌ → “She suggested leaving early.” ✅ — suggest is gerund-only. (Rule 3)
4. “Avoid to use jargon.” ❌ → “Avoid using jargon.” ✅ — avoid is gerund-only.
5. “I stopped to smoke five years ago.” ❌ (means “I paused to have a cigarette”) → “I stopped smoking five years ago.” ✅ — meaning-change verb. (Rule 6)

The fix for all five is the same: identify the front verb (or preposition), then check the list. Within two weeks of consciously running that check, the errors stop happening. Within six weeks, the right form will sound automatic — which is exactly how native speakers process the same choice.

Quick Practice: Test Your Gerund vs Infinitive | 小測驗

Choose V-ing or to + V for each blank. Answers below.

1. I look forward to ___ (hear) from you.
2. She decided ___ (study) in Canada next year.
3. Do you mind ___ (close) the door?
4. Remember ___ (lock) the office before you leave.
5. He’s good at ___ (negotiate) with suppliers.
6. We can’t afford ___ (lose) this client.
7. I enjoy ___ (read) on the MRT.
8. She managed ___ (finish) the deck before the meeting.

Answers: 1. hearing 2. to study 3. closing 4. to lock 5. negotiating 6. to lose 7. reading 8. to finish. If you got six or more right, your foundation is solid — bookmark Rule 6 and move on. If you got fewer than six, re-read Rule 3 and Rule 4 and drill the verb-list tables. Vocabulary memorisation work here pays off forever — see our vocabulary-building methods for the technique most native speakers use without realising it.

Watch: Gerund or Infinitive Explained with 50 Verbs

For a visual walkthrough that mirrors the verb-list approach above, English with Greg covers 50 common verbs in one go — useful as a final review before a TOEIC test or a job interview.

Final Word: Treat the Verb Lists Like Vocabulary, Not Like Grammar

The single most useful mindset shift on this topic is to stop hunting for a logical rule that explains why enjoy takes V-ing and want takes to V. There isn’t one. These are vocabulary items disguised as grammar — native speakers learned them word by word over twenty years, and the shortcut for adult learners is to do the same with the high-frequency 50 in a single weekend. Make a flashcard deck with one verb per card, drill it for fifteen minutes a day for a week, and the entire topic permanently moves from “I have to think about this” to “I just know.”

Sources

1. Cambridge Dictionary — Verbs followed by a to-infinitive — full verb list with example sentences.
2. British Council Learn English — Gerunds — reference grammar guide on the gerund form.
3. BBC Learning English — Verb patterns: gerund or infinitive — short lesson with audio examples.
4. Merriam-Webster — The Difference Between a Gerund and an Infinitive — clear explanation of the semantic split.