To knock down the toy clowns was the biggest challenge at the school festival.
Bold phrases is infinitive
Gerund form : To knocking down the toy clowns was the biggest challenge at the school festivals .
In an infinitive phrase, the modifiers might include articles, adjectives, objects, or adverbs. An infinitive phrase begins with the infinitive verb, usually with the word "to" in front. Here are some examples of infinitive phrases: Peter loved to play guitar
A gerund is that the –ing form of a verb that functions the same as a noun. for example, “Running is fun.” during this sentence, “running” is that the gerund. It acts a bit like a noun
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