Question

Fill in the blank with the most appropriate word.
Betty couldn't help ____ when Oscar fell down.

• A. laugh
• B. at laughing
• C. to laugh
• D. laughing

Answer 1

Answer: (D)

laughing

Let’s examine the sentence: “Betty couldn't help ____ when Oscar fell down.” The sentence specifies a state of action that Betty gets into.’ As the sentence talks about the state of action, and not the action itself, it requires a noun or a gerund. The gerund always has the same function as a noun (although it looks like a verb). The gerund ends in ‘ing.’ As Option D fulfils this requirement, so it is the correct answer. All the other options cannot be used as they would make the sentence meaningless.