In the sentence:
Driving carelessly increases the likelihood of an accident
The gerund phrase is ‘Driving carelessly’.
Gerund are verbs used as subjects in a sentence with the root word added by ‘-ing’. Verbs are simply known as the ‘action’ words – may it be mental, physical or mechanical. Nouns are names of a person, animal, place, event, etc. It could be proper or common noun.
The gerund phrase in this sentence is "Driving carelessly". A gerund phrase starts with a gerund (word with "ing") followed by complements. They function as a noun in the sentence and they have different uses depending on its position.
In this sentence, the gerund phrase "Driving carelessly" is acting as the subject of the verb "increase".
Gerund phrases can be subjects, subject complements or objects within a sentence.
