Final answer:
The word 'old' in the sentence is an adjective because it describes the noun 'friend', indicating a type of friend. Adjectives provide additional information about the nouns or pronouns they modify.
Step-by-step explanation:
The question 'He is an old friend of mine' asks us to identify the part of speech for the word in bold, which is 'old'. In this context, 'old' functions as an adjective because it describes the noun 'friend' by specifying the kind of friend, indicating a longstanding relationship. When determining parts of speech like nouns, adjectives, verbs, and adverbs, it's important to consider how the word is used in the sentence and what it is modifying or describing.
In English grammar, parts of speech are the building blocks of sentences. An adjective modifies a noun or pronoun by providing additional information about it, such as color, size, age, or condition. Keeping this in mind can assist you when you're trying to choose the most effective verb forms for a given text, whether it's in the present or past tense. For instance, discussing John Lewis's courageous actions would require the appropriate tense to convey the events accurately.
When editing for conciseness, it is crucial to omit needless words and phrases to create clear and impactful sentences. This principle is demonstrated when rewriting sentences to reduce wordiness, such as condensing a 49-word sentence down to a core three-word directive: 'Omit needless words.'