What is the structure of a present participle?

The structure of a present participle is correctly identified as a verb followed by the suffix -ING. Present participles are used in various ways in sentences, primarily in forming progressive tenses and as adjectives. When combined with helping verbs, present participles create continuous tenses that express ongoing actions.

For example, in the sentence "She is running," "running" is the present participle that describes the action of the subject "she" in a continuous manner, indicating that the action is currently in progress. This structure emphasizes the action rather than the completion of the action, which is why it is crucial to include a helping verb alongside the present participle.

The other options do not accurately represent the structure of a present participle, as they reference different forms or structures that do not encompass the present participle form used in progressive tenses.