English is a fluid language. Nouns sometimes morph into verbs — transition, access and impact, in common usage of recent years. (Not that I necessarily approve. When n doubt, check AP style.) And verbs can be nouns in two of their forms: infinitives and gerunds.
An infinitive is to plus the base form of the verb — to be, to have, to go, to stay, etc. It is used as a noun:
I love to swim. (What do I love? To swim. The infinitive is the direct object, and objects are nouns or pronouns.)
A gerund is essentially the verb’s present participle — base + -ing — used as a noun: I love swimming.
In that case, where love is the verb in both sentences, the two forms are interchangeable and equally correct. That’s not always the case; some verbs demand to be followed by an infinitive, some by a gerund. An example from student work this semester:
Shoe repair shops tend to gather in big cities like New York because people who live there can afford buying expensive footwear or spend money on extra protective or orthopedic work.
Tend takes the infinitive; you always tend to do something. Afford, on the other hand, could go either way, although afford to buy is more common. But notice that another verb follows: spend. Because it’s of equal weight in the sentence to buy, it needs to be parallel — the same form:
. . . people who live there can afford buying expensive footwear or spending money on extra protective or orthopedic work.
. . . people who live there can afford to buy expensive footwear or (to) spend money on extra protective or orthopedic work.
In the case of spend, the to is optional. The form is easily understood from context to be an infinitive, and it’s safe to drop it. The same is true in another student’s sentence:
This experience helps people (to) understand the blind world.
After help, you generally don’t need to unless the sentence sounds awkward without it.
Jason Hansman, senior program manager at IAVA, said veterans’ major challenge is to learn how to promote themselves.
Learn or learning? In this case, either is correct:
Hansman said veterans’ major challenge is learning how to promote themselves.
She suggested to look at the company’s website called “The Exceptional Cranberry” to know more about the healthfulness of cranberries.
No. Suggest takes the gerund, so here it needs to be looking.
How do you know which verbs take infinitives, which take gerunds and which take either? Listen to the way people speak; pay attention when you’re reading; and consult lists like this one on TestYourEnglish.net or this one on EngVid.com, which incudes an interactive quiz.
Since gerunds are used as nouns, nouns directly before them need to be possessive. Not:
The idea of customers actually going to the store for returns appeals to him.
The idea of customers’ actually going to the store for returns appeals to him.