การใช้ to infinitive และหน้าที่ของ to infinitive ในทางไวยากรณ์
เราสามารถใช้ to infinitive ในรูปของการกระทำที่กำลังดำเนินอยู่อย่างต่อเนื่อง(continuous), รูปของการกระทำที่สำเร็จสมบูรณ์ (perfect) และรูปของกรรมวาจก (passive) ได้ เช่น
- Joe seems to like his course. (รูป to infinitive)
- He seems to be settling in well. (to infinitive ในรูป continuous )
- He seems to have made a lot of friends. (to infinitive ในรูปของ perfect)
- He seems to have been working hard. (to infinitive ในรูปของ perfect continuous)
- He seems to be regarded as a good student. (to infinitive ในรูป passive)
- He seems to have been awarded excellent marks. (to infinitive ในรูปของ perfect passive)
เช่นเดียวกับ Gerund กล่าวคือ รูปกริยา to infinitive ในทางไวยากรณ์ เราใช้ทำหน้าที่ได้หลายอย่างดังนี้:
1. เป็นกรรมของกริยา เช่น
- I want to win.
- We intend to complain.
2. เป็นประธานของกริยา เช่น
- To fail now would be very frustrating.
- To tell the truth can be very difficult.
3. เป็นส่วนเติมเต็ม (complement)โดยวางไว้หลัง linking verb เช่น
- To understand is to forgive.
- The purpose of this valve is to control the flow.
- My plan is to spend two nights in Taipei.
- The idea is to meet at 6.30 for dinner.
เราจะใช้รูปกริยา to infinitive เมื่อไหร่?
คำตอบคือ เราสามารถใช้ to infinitive ตามหลัง verbs ต่างๆมากมายหลายคำ เช่น
- David and I agreed to meet at 4 o'clock.
- I'll arrange to see the dentist straight away.
- I hope to go university.
- I managed to repair the lock.
- I'm going to meet Philip tomorrow.
- We intend to move house soon.
- I'm longing to see you.
- I like to get up early in the mornings.
- I'd hate to make a mistake.
- I'd love to go to the museum.
- Maggie began to cry.
- It's starting to rain.
- Jane continued to read her novel.
- Joe has decided to train as a doctor.
- Paul has learnt to swim.
- I didn't mean to hurt you.
- Mum promised to drive me to the class.
- Dad refused to sign the document.
- We want to have a meal before the concert.
- Try to keep calm.
- They seem to approve of my idea.
- John appeared to know all the answers.
- I hadn't planned to take a holiday just yet.
- Dad refused to give me any more money.
- Charlie offered to cook dinner for us all.
- Did you expect to succeed?
- I have (or have got) leave in five minutes.
- I've forgotten to bring my passport.
- Do you need to change any money?
- Did you remember to close the windows?
- You deserved to win.
- I prefer to write my novels by hand.
- I can't bear to cause unhappiness.
- We regret to announce that tonight's performance is cancelled.
ในรูปประโยคปฏิเสธ เราเติม not หรือ never ไว้หน้ารูปกริยา to infinitive เช่น
- Promise never to tell anyone.
- I prefer not to drive at night.
- She seemed not to realize her danger.
- I managed not to laugh.
- Try not to get so angry.
กริยาบางคำ ตามด้วยรูปกรรม (object) ก่อนแล้วจึงตามด้วยรูปกริยา to infinitive เช่น
- The travel agency allowed us to change our booking.
- Sue asked me to help her.
- The policeman told us sto wait.
- Anne persuaded me to join her choir.
- Remind me to buy more noodles.
- We expect you to do your best.
- Who taught those girls to dance?
- We want you all to concentrate.
- I forbid you to use my car.
- The captain permitted the passengers to leave the ship.
- The doctor advised us to take vitamin pills.
- I warned Maggie not to leave money around.
รูปกรรม (object) จะทำหน้าที่เป็นประธาน (subject)ในประโยคกรรมวาจก เช่น
- Maggie was warned not to leave any money around.
- We were advised by the doctor to take vitamin pills.
- You are forbiden to use my car.
รูป verb + for + object (noun or pronoun) + to infinitive เช่น
- arrange for: I've arranged for you to see the dentist.
- ask for: We asked for our bags to be delivered to our hotel.
- long for: I was longing for the lesson to end.
- wait for: Wait for me to give the signal.
เราสามารถใช้รูปกริยา to infinitive ตามหลังคำคุณศัพท์ (adjective) บางคำ เช่น
- Julie was afraid to cross the road.
- I'm so glad to see you.
- I'm reluctant to lend you any more money.
- I'm sorry to report that we lost the match.
- I'm pleased to say the children behaved excellently.
- The kids are all keen to be in the team.
- I'm determined to get that job.
- They were eager to hear the latest news.
- I'm so relieved to know the money arrived safely.
- Jim was the first to arrive.
- Helen was the last to leave.
- Dave was the only one to apologize. (Dave was the only one who did apologize)
- Dan was likely to win.
- We're unlikely to meet again.
- I'm sure to see Jane in the next few days.
- It's certain to rain tomorrow.
- Anne is bound to be late.
- I'm liable to forget.
- The train's due to leave in two minutes.
- You're welcome to come with me.
- Mum's willing to help.
- Were you able to contact her?
- Are you ready to begin?
- I'm not prepared to tolerate this misbehaviour.
- I was wrong to blame Susie for the mess.
- You were lucky to escape!
- I was silly to give up.
รูปประธานกลายเป็นกรรม (object) ของ to infinitive
คำนาม หรือ คำสรรพนาม ซึ่งทำหน้าที่เป็นประธานของรูป linking verb (กริยาที่ใช้เชื่อมประโยค) + คำคุณศัพท์ (adjective) สามารถใช้เป็นกรรม (objective) ของกริยา to infinitive ที่ตามมา ในภาคส่วนเติมเต็ม (complement) ของประโยค เช่น
- Science programmes are so interesting to watch.
- Are these nuts good to eat?
- English verbs are not very easy to learn.
- Those maths problems were difficult to solve.
- These sums are quite simple to do.
- The possibilities are frightening to contemplate.
- I prefer children as models - they're delightful to paint.
ประธานของ linking verb อาจจะเป็นรูปกรรมของคำบุพบท (preposition) ที่ใช้กับ to infinitive เช่น
- This futon is very comfortable to sleep on.
- Elizabeth is fascinating to talk to.
- She's so entertaining to be with.
adjective + noun + to infinitive เช่น
- That's an unusual question to ask.
- Who's the best person to consult?
- This is a comfortable futon to sleep on.
- Elizabeth is a fascinating girl to talk to.
verb + direct object + adjective + noun (indirect object) + to infinitive เช่น
- We considered you the right person to appoint.
- I found Ruth a delightful companion to travel with.
คำกริยาวิเศษณ์ (adverb) + to infinitive เช่น
- Cheerio - I'm off to visit Peter.
- Dad was about to serve lunch.
- Sam is out to get the top job. (=He's determined to get it)
noun + to infinitive เช่น
- I've no desire to be famous.
- I felt an inclination to hit him.
- We respected Dad's wish to be barried in his native village.
- Kate had no ambition to travel the world.
- There's no need to apologize.
- Jim's decision to retire surprised us all.
- There'll be an opportunity to ask questions later.
- I need time to think.
- John sent me a reminder to book seats.
- We waited for the order to advance.
- You were a fool not to claim the reward.
ประธาน (subject)เป็นกรรม (object)ของกริยา to infinitive ในภาคเติมเต็ม (complement)ของประโยค
ประธานของกริยาเชื่อม linking verb + คำนาม ใช้เป็นกรรม (object) ของกริยา to infinitive (หรือ กริยา to infinitive + preposition) ในภาคเติมเต็มของประโยค เช่น
- Your cooking is always a pleasure to sample.
- These children are a delight to teach.
- Cricket is such a bore to take part in.
- The games must be a nightmare to organize.
คำนาม + กริยา to infinitive เช่น
- I phoned for a taxi to take us to the airport.
- Here's a pill to help you sleep.
- We employed a guide to lead us up the mountain.
- Have you got a video to keep the children quiet?
- Take a book to read in case you get bored.
- Bring a mat to sit on.
- We've got a problem to discuss.
- I've a sin to confess.
คำสรรพนามที่ไม่ชี้เฉพาะเจาะจง (indefinite pronouns) และคำบอกปริมาณที่ไม่ชี้เฉพาะเจาะจง (indifinite quantifiers) ถูกใช้บ่อยๆกับรูปกริยา to infinitive เพื่อแสดงความรู้สึกถึงวัตถุประสงค์ (expressing purpose) เช่น
- Have you all got something to eat?
- I've got nothing to wear.
- Isn't there anything else to watch?
- We have plenty to get on with.
- The children get lots to do on the farm.
- Have you any goods to declare?
- Is there anywhere to talk privately?
โครงสร้างที่มีรูปกริยา to infinitive มักจะขึ้นต้นประโยคด้วยรูปประโยคคือ It is, It was เป็นต้น ตามด้วย คำคุณศัพท์ (adjective) หรือคำนาม (noun)
(It is (หรือ was, เป็นต้น) + adjective หรือ noun + to infinitive)
- It's silly to argue.
- It was kind of you to visit my mother.
- It was stupid of me not to note the time.
- It's a priviledge to work with you.
- It would be a shame to give up now.
- It's my ambition to write a best-seller.
- It's my plan to finish most of the work by the end of June.
- It's nice to be home.
- It's never a good idea to go without sleep.
- Is it time to leave?
- It's important to plan your day in advance.
- It's sensible to check in early.
- It was a pleasure to meet you.
- It will be a good opportunity to see Hong Kong.
บทบาทของคำบุพบท for เมื่อใช้กับ to infinitive
- I've arranged for the furniture to go into storage.
- I asked for the date to be changed.
โครงสร้างเดียวกันนี้ตามด้วยคำนาม หรือ คำคุณศัพท์บางคำ เช่น
- The idea is for everyone to stay at our house.
- It's a great opportunity for us to meet the students.
- Isn't it time for us to leave?
- It's ridiculous for us all to squeeze into one car.
- The situation is difficult for strangers to understand.
- Is it possible for you all to be ready by nine?
- It's impossible for them to do the journey in two hours!
- Are these nuts OK for humans to eat?
รูป enough, too + to infinitive เช่น
- Are you old enough to drive?
- It's too late to telephone now.
- I haven't enough money to pay the bill.
- The part is too long for a single actor to play.
- It's too wet to go for a walk.
- He's tall enough to touch the ceiling.
- I hope I've worked hard enough to pass my exams.
- I've been too busy to read the papers.
- I'm too short-sighted to risk driving without spectacles.
- It's too foggy to see the island today.
- Some of the exercises ar etoo strenuous for girls to perform.
- Is the sea warm enough to swim in?
- Are the puzzles easy enough for children to solve?
- In London it was hot enough to go out without a coat.
รูป be + to infinitive ใช้ในประโยคคำสั่งที่หนักแน่นเด็ดขาด หรืออ้างถึงแผนการที่ได้ดำเนินการเรียบร้อยแล้ว เช่น
- You are to stop writing immediately.
- You are to be back before midnight.
- You are to apologize to your mother for your rudeness.
- We are to report to headquarters at eight o'clock.
- The Minister is to return to Singapore later this evening.
- The celebrations were to have been held last week, but there was a delay.
- Your e-mail message said I was to come straight here.
- The wedding is not to take place after all.
รูป wh-question words + to infinitive ใช้แสดงถึงการสอบถาม, การรับทราบ, การเรียนรู้และการเสนอแนะ เช่น
- Helen is learning how to drive.
- Sue asked me where to buy the best computer.
- Dad told me which key to press.
- I didn't know what to do.
- I had no idea who to ask.
- Let me know how many copies to print.
- The nurse told me which pills to take.
- I can't think what to write.
- Tell me when to stop pouring.
- Could you remind me how many flour to use?
- Does the recipe say how long to boil the mixture for?
- I'm wondering what clothes to buy for my trip.
รูป in order และ so as + to infinitive เพื่อแสดงถึงวัตถุประสงค์ เช่น
- Arrive early so as to get a good seat.
- Sit near the front in order to get a good view.
แต่เราสามารถใช้ to infinitive เพื่อแสดงถึงวัตถุประสงค์ได้ด้วยตัวมันเอง เช่น
- The baby was taken to the clinic to get her injections.
- I'm going to the shops to buy some food.
- To speed up the work, we employed extra staff.
รูป to infinitive ที่ใช้กับสำนวนแสดงวัตถุประสงค์บางอย่าง นิยมวาง to infinitive เช่นนั้นไว้ต้นประโยค เช่น
- To be fair, she didn't mean to cause trouble.
- To be honest, I didn't like the play much.
- To put it more simply, a fact is just an interpretation.