The difference between Gerunds and Infinitives

Gerunds (e.g. learning) and infinitives (e.g. to learn) function as nouns. In other words, they can be subjects of verbs, objects of verbs or objects of prepositions. Some verbs require gerunds as objects while others require infinitives. Sometimes words that come before the blank will indicate whether a gerund or infinitive is needed:

1. The rooms are available for anyone who plans on _______ in North Carolina for a few days.
    a) to stay
    b) staying
    c) stay
    d) stayed
In the example above, the preposition “on” comes before the missing word. Usually, a preposition is followed by a noun, a pronoun, or a gerund (but never an infinitive). Therefore, the correct answer is b) staying.

Look at the next example:
2. You can't expect _________ everything in a few days.
    a) to remember
    b) remember
    c) remembering
    d) that remember
The verb “expect” is followed by an infinitive which is the object of “expect”, so the answer is a) to remember.