In imperative sentences, the subject is usually omitted, the verb is used as the predicate and the prototype is used.
When verbs are used as adverbials to express passive meanings in sentences, they should use past participles.
When verbs are used as adverbials to express positive meanings in sentences, the present participle form is used.
When a verb is the subject in a sentence, it can be in the form of gerund or infinitive.