Improving Sentence Grammar: Adjectives vs. Adverbs

The original sentence is: "This has sharp decreased the cases of water-borne diseases." We need to improve the underlined part, "sharp decreased," to make the sentence grammatically correct.

Let's analyse the structure of the underlined phrase and the sentence.

• "decreased" is a verb, specifically the past participle form used here with the auxiliary verb "has" to form the present perfect tense.
• "sharp" is an adjective.

In English grammar, adjectives are used to modify nouns, while adverbs are used to modify verbs, adjectives, or other adverbs. In the phrase "sharp decreased," the word "sharp" is attempting to modify the verb "decreased." An adjective cannot modify a verb.

Therefore, we need an adverb to modify the verb "decreased." The adverbial form of the adjective "sharp" is "sharply."

Analyzing the Options for Sentence Improvement

Let's look at the given options and see which one correctly uses an adverb to modify the verb "decreased."

• Option 1: No improvement

  This option suggests the original sentence is correct. As we've established, "sharp decreased" is grammatically incorrect because an adjective ("sharp") is modifying a verb ("decreased"). So, this option is incorrect.

• Option 2: sharply decreased

  In this option, "sharply" is an adverb modifying the verb "decreased." This structure correctly uses an adverb to describe how the cases decreased. This fits the grammatical requirement.

• Option 3: sharp decrease

  Here, "decrease" is used as a noun (e.g., "a decrease"). "sharp" is an adjective modifying the noun "decrease." While "sharp decrease" is a grammatically correct phrase in isolation (e.g., "There was a sharp decrease"), it does not fit the sentence structure "This has...". The verb form "decreased" is required after "has" in this context.

• Option 4: sharper decreases

  In this option, "sharper" is a comparative adjective (used for comparing two things), and "decreases" is a plural noun. This phrase is plural and in noun form, which does not fit the singular subject "This" or the requirement for a past participle verb after "has."

Conclusion on Sentence Improvement

Based on the analysis, the only option that correctly replaces the underlined phrase with an adverb modifying the verb is "sharply decreased."

The improved sentence is: "This has sharply decreased the cases of water-borne diseases."

The correct answer is Option 2: sharply decreased.

Revision Table: Adjectives vs. Adverbs

Additional Information: Understanding Sentence Structure

Understanding the basic parts of a sentence and their functions is crucial for correct grammar. In the sentence "This has sharply decreased the cases of water-borne diseases":

• "This" is the subject.
• "has decreased" is the verb phrase (present perfect tense).
• "sharply" is an adverb modifying the verb "decreased," telling us how the decrease happened.
• "the cases of water-borne diseases" is the object receiving the action of the verb.

Incorrectly using an adjective where an adverb is needed is a common grammatical error. Always check if the word is modifying a noun (use an adjective) or a verb, adjective, or adverb (use an adverb).