A. To-infinitive Forms
1. From a verb
a. In active forms
Example:
- do becomes to do, to be doing, to have done (from do-did-done), and to have been doing.
b. In passive forms
Example:
- do becomes to be done, and to have been done.
2. From a non-verb
a. From an adjective
Example:
- late becomes to be late.
b. From a noun phrase
Example:
- an engineer becomes to be an engineer.
c. From an adverbial of place
Example:
- here becomes to be here.
d. From a prepositional phrase
Example:
- with you becomes to be with you.
3. In negative forms
Examples:
- do becomes not to do.
- late becomes not to be late.
B. To-infinitive Functions
1. As a subject
Examples:
- To make mistakes (subject) is easy (predicate). (Older English)
- It (temporary subject) is easy (predicate) to make mistakes (the real subject). (Modern English)
- (For me) to do that is impossible.
- To do that is impossible (for me).
- It is (im)possible (for me / you / him / her / us / them) to do that.
- It is (un)likely (for them) to postpone the meeting.
- It is (un)necessary (for us) to create web pages for a personal website.
- It took him ten months to conduct such research.
- It takes me ten minutes to get to (my) work.
- It will take you ten hours to get there.
- It takes time to write programs in high level languages.
2. As a subjective complement
Examples:
- Their ambition is to obtain good jobs.
- The role of the operating system is to communicate directly with the hardware.
- One of the key functions of the operating system is to establish a user interface.
- One of the important functions of the computer is to process large amounts of data quickly.
3. As the object of a verb
Examples:
- I want to upgrade my computer.
- You seem to be enjoying the film.
- The survey appears to have revealed some interesting facts.
- He seems to be happy.
- She wants to be a systems analyst.
- They promised to be here at six o’clock.
- He happened to be out when I called him.
- She tends to talk too much.
- How old were you when you learned to operate a computer?
- He agreed to lend me $ 100,000.
- She refused to comment on his involvement.
- He forgot to bring me the PC magazine.
- I always remember to back up important files.
- There were a lot of traffic-jams this morning, but we managed to get to (my) work on time.
- The operating system failed to boot although she had tried to start up the computer several times.
- He is lazy. He needs to work harder.
- If you want to link your PC with a mainframe, you will need to install a network.
- We are planning to install LAN (Local Area Network).
- They would like to see the manager.
- Quite few of the companies can afford to purchase a mainframe.
- I never thought to see you here.
- I prefer not to start early.
- I tried to get in touch with the manager this morning, but I missed him again.
- My cheap PC seems to be (just) as good as John’s expensive one.
- The professional programmer wants to create and sell a program for use in language learning.
4. As an objective complement
Examples:
- She asked me to fix her PC.
- They advised me to accept the offer of the job.
- The Help facility enables users to get advice on most problems.
- Windows allows you to display two different folders at the same time.
- Voice recognition software helps disabled users (to) access computers.
- The college lecturer wanted his students to learn the principles of programming.
- They would like us to co-operate with them.
5. To modify an adjective
Examples:
- We are very sorry not to be able to give you a definite reply in respect of the matter.
- He was surprised to learn how much he had spent.
6. To modify the words "enough" and "too"
Examples:
- Do you think he is good enough to become our manager?
- This question is too difficult (for me) to answer.
7. To modify a noun phrase
Examples:
- I have a lot of work to do.
- We have some important business to take care of.
- All user requests to access a database are handled by the database management system.
- I don’t have the courage to ask my employer for a raise in pay.
- The power to help others depends on the power to help oneself.
- The next question to consider (to be considered) was the crucial one.
- I need a box to hold my CDs.
- I don’t have enough money to buy a notebook computer.
8. To reveal a purpose
Examples:
- They went to New York to do business.
- He came to London to look for a job.
- He uploaded a website to advertise his travel company.
- He moved to Jakarta (in order / so as) to have a better opportunity to find a good position.
- She subscribes to many different PC magazines and reads them all to keep up with the development of computer technology.
9. To be used after a question word
Examples:
- The problem is where to get the money.
- He consulted his stockbroker on how to invest his money.
- The computer operator showed me how to insert graphics into a document.
- The office manager will explain to the new secretary where to work and what to do.