Unit 3. Infinitives and Gerunds
FOCUS
What is wrong with the following sentence?
| The cougar likes hunt under the cover of darkness, when it uses its keen night vision to find prey. |
Cougars like something. What does it like? It likes to hunt? There must be a noun as an object after the verb like, but hunt is a verb. The above sentence is wrong and needs to be revised. There are two ways to modify it, one is to use the infinitive to hunt, and the other is to use the gerund hunting. The two correct expressions are:
| The cougar likes to hunt under the cover of darkness, when it uses its keen night vision to find prey. The cougar likes hunting under the cover of darkness, when it uses its keen night vision to find prey. |
What is wrong with the following sentence?
| Many chefs use fruit for add color and texture to familiar dishes made of meats and grains. |
Many chefs do something with fruit. What to do? The for add structure is wrong because there must be a noun as an object after the preposition for, but add is a verb. There are two ways to modify it, one is to replace for add with to add, and the other is to change add to adding. The two correct expressions are:
| Many chefs use fruit to add color and texture to familiar dishes made of meats and grains. Many chefs use fruit for adding color and texture to familiar dishes made of meats and grains. |
STUDY
Infinitives and gerunds are non-predicate forms of verbs. The non-predicate form of a verb has a different function in the sentence than the verb and cannot serve as a predicate. The part of speech of infinitive and gerund is not verb. Both can be used as nouns, and the infinitive can also be used as adjective or adverb.
| Infinitives | Gerunds |
| to do to feel to swim to trade | doing feeling swimming trading |
Although neither infinitives nor gerunds are verbs, they have some verb characteristics. For example, like verbs, infinitives and gerunds can have modifiers and direct objects.
An infinitive with a modifier or object is called an infinitive phrase. In the following example sentence, the infinitive to represent is followed by the direct object numbers, and to represent numbers is an infinitive phrase.
| The Roman abacus used pebbles to represent numbers. Infin. DO |
A gerund with a modifier and an object is called a gerund phrase. There are two gerund phrases in the following example sentence. The gerund checking has the adverb frequently as its modifier and your rearview mirror as its direct object. The gerund driving has the adjective safe as its modifier.
| Frequently checking your rearview mirror is a good tip for safe driving. Adv. Ger. DO Adj. Ger. |
Infinitive phrases and gerund phrases are both common structures.
| Infinitive Phrases | Gerund Phrases |
| to think creatively to speak Korean not to ask a question to walk to the bus stop | wearing sunglasses clear writing freely deciding the mining of silver |
The infinitive is composed of to and the base form of the verb.
| to + verb base form |
Infinitive phrases can function as nouns, adjectives, adjective complements, or adverbs. The infinitive cannot be the object of a preposition.
| Function | Examples |
| subject | To dance professionally requires years of training. To own a home has always been part of the American dream. |
| subject complement | The purpose of a committee is to study an issue. The main purpose of the Federal Reserve System is to control the money supply. |
| direct object | Some babies begin to walk at the age of nine months. Jane Addams tried to put her education to use in social work. |
| adjective | A cougar has the ability to see in the dark. Comedians have the power to make people laugh. |
| adjective complement | Many people find it convenient to shop online. It is becoming common to see office workers dressing casually on Fridays. |
| adverb | Sensors are designed to detect the presence of specific substances. To focus on an image, a photographer looks through the camera’s viewfinder. |
When the infinitive expresses a negative meaning, not must be in front of it.
| I’ve decided not to apply for the job in the library. That sign warns people not to park cars or bicycles in the loading zone. |
When two infinitives appear side by side, the to in the second infinitive can be omitted. When there are three or more infinitives in parallel, starting from the second infinitive, to can either appear or be omitted.
| Marine biologists are attempting to monitor and control the krill populations. The liver manages to process proteins, to produce bile, and to cleanse the blood. The liver manages to process proteins, produce bile, and cleanse the blood. |
The infinitive can be used after causative verbs such as get and help. Among them, after the causative verb help, to can be retained or omitted.
| My uncle always gets me to laugh at his corny jokes. The World Bank helps member nations to develop their economies. The World Bank helps member nations develop their economies. |
The infinitive can be used in the passive voice.
| Most teenagers want to be taken seriously by adults. To be seen at night by drivers, bicyclists should wear reflective clothing. |
The infinitive can be the direct object of the following verbs.
| Verb + Infinitive | ||||
| advise* | claim | fail | need | seem |
| afford | come | forbid* | neglect | serve |
| agree | command* | force* | offer | strive |
| allow* | compel* | get | order* | struggle |
| appear | consent | help | permit* | teach* |
| appoint* | convince* | hesitate | persuade* | tell* |
| arrange | dare | hire* | plan | tend |
| ask | decide | hope | prepare | threaten |
| attempt | demand | instruct* | pretend | try |
| be | deserve | intend | proceed | urge* |
| beg | direct* | invite* | promise | wait |
| care | enable* | learn | prove | want |
| cause* | encourage* | manage | refuse | warn* |
| challenge* | endeavor | mean (intend) | remind* | wish |
| choose | expect | motivate* | require* | work |
| Do you care to comment on the lecture? Please do not hesitate to call if you have any questions. We need to use wind, water, and solar power as alternative energy sources. Shrubs tend to have several stems branching out from the main stem near the ground. |
Note: In the table above, verbs marked with * must be followed by an indirect object: verb + indirect object + infinitive. l In the following examples, indirect objects are expressed in italics.
| President Jefferson appointed Meriwether Lewis to lead the expedition. Adaptations enable some organisms to live outside their ideal temperature range. My grandfather taught my uncle to drive a tractor when he was twelve years old. |
Infinitives can be used as complements of the following adjectives.
| Adjective + Infinitive | ||||
| able | delighted | glad | necessary | sad |
| afraid | determined | good | pleased | shocked |
| amazed | difficult | happy | possible | sorry |
| careful | disappointed | hesitant | prepared | strange |
| common | eager | honored | proud | surprised |
| content | easy | important | ready | usual |
| dangerous | essential | motivated | relieved | willing |
| Computers are able to perform increasingly sophisticated functions. Project plans must include the steps that are necessary to achieve success. I was sorry to hear about your accident. |
Sometimes, the structure “for + noun” appears between the adjective and the infinitive.
| It is dangerous for backpackers to hike in the wilderness alone. It is very important for everyone to remember the rules of the game. |
5.Gerunds
A gerund is formed by adding -ing to the base form of the verb.
Verb base form + -ing
Gerunds can function as nouns in sentences.
| Function | Examples |
| subject | Drawing the human face is a challenge for artists. Adapting to change is necessary for survival. |
| subject complement | The most common pastime is watching television. An important part of a speech is getting the audience’s attention. |
| direct object | Teachers recommend writing an outline for an essay. Marian Anderson began singing opera to help support her mother and sisters. |
| Function | Examples |
| object of preposition | We know about past climate by looking at the geological record. The raccoon is known for washing its food before eating. |
Note: Gerunds are uncountable and usually do not take an article (see Unit 11). There is one exception: the definite article the must be added to the structure of “gerund + of + noun”.
| Historically, responsibility for the rearing of children belonged to the parents. |
Gerunds can be the direct objects of the following verbs or verb phrases.
| Verb + Gerund | ||||
| admit | consider | imagine | object to | report |
| aid in | count on | insist on | postpone | resent |
| anticipate | delay | involve | practice | resist |
| appreciate | deny | keep/keep on | prevent | resume |
| approve of | depend on | look forward to | put off | risk |
| avoid | discuss | mean (intend) | recall | succeed in |
| believe in | enjoy | mention | recollect | suggest |
| call for | finish | mind | recommend | think about/of |
| complete | give up | miss | rely on | tolerate |
| Most professors do not approve of using mobile telephones in class. The committee chairman will consider adding two items to the agenda. We look forward to visiting you during spring break. After a six-month delay, the company resumed importing raw materials. |
7.Infinitive or gerund as object
The infinitive or gerund can be the direct object of the following verbs.
| Verb + Infinitive or Gerund | ||||
| advise | begin | forbid | prefer | start |
| allow | continue | forget* | regret* | stop* |
| attempt | dislike | like | remember* | try |
The following two sentences have the same meaning.
| People started to build skyscrapers in the nineteenth century. People started building skyscrapers in the nineteenth century. |
After the verb marked with *, the infinitive and the gerund express different meanings. The following two sentences have different meanings.
| Dave must remember to feed the dog. Dave must remember feeding the dog. |
In the first sentence, the dog has not been fed yet and Dave should feed the dog. In the second sentence, the dog has been fed, and Dave must remember this.
When expressing tools, materials and methods, the verb use is often followed by an infinitive phrase. Use can also be paired with a gerund phrase “for + gerund”, where the gerund serves as the object of the preposition for. The two sentences in each group below mean the same thing.
| A surgeon uses a lancet to make small incisions. A surgeon uses a lancet for making small incisions. A centrifuge is used to separate particles from a liquid. A centrifuge is used for separating particles from a liquid. Many designers have used natural objects to decorate rooms. Many designers have used natural objects for decorating rooms. |
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