Improve the bracketed part of the sentence by choosing the correct verb form: Affirmations are positive statements that (describes) a desired situation or goal and are often repeated.

Introduction / Context:
This sentence improvement question focuses on subject verb agreement, especially in relative clauses. The sentence defines "affirmations" and explains what they do. The bracketed verb "describes" must agree in number with its subject, which is "statements."

Given Data / Assumptions:

• The main noun is "affirmations," which are defined as "positive statements."
• The clause "that (describes) a desired situation or goal" modifies "statements."
• The real grammatical subject of "describes" is "that" referring back to "statements."
• "Statements" is a plural noun.

Concept / Approach:
In a relative clause starting with "that," the verb must agree with the noun the relative pronoun refers to. Here, "that" stands for "statements," which is plural. Therefore, the verb in the clause must be plural as well, that is, "describe," not "describes." The correct structure is "statements that describe a desired situation or goal."

Step-by-Step Solution:
Step 1: Identify the noun that "that" is referring to. It refers to "statements." Step 2: Note that "statements" is plural. Step 3: Apply subject verb agreement: a plural subject requires a plural verb form in the present tense. Step 4: Change "describes" to "describe" to match the plural subject. Step 5: Read the full sentence: "Affirmations are positive statements that describe a desired situation or goal and are often repeated." It now follows correct grammar rules.

Verification / Alternative check:
Compare with similar structures: "Books that describe history are popular," or "Devices that measure temperature are called thermometers." In each case, "that" refers to a plural noun ("books" or "devices"), so the verb is plural ("describe," "measure"). This pattern confirms that "describe" is the correct verb form in the given sentence.

Why Other Options Are Wrong:
Option A: "describing" would change the structure to a participial phrase, which is possible but less appropriate for a clear definition of what affirmations are. Option C: "is describing" is singular and progressive, not matching the plural noun "statements" and not fitting the general descriptive nature of the sentence. Option D: "No improvement" is wrong because "describes" does not agree with the plural noun "statements."

Common Pitfalls:
Subject verb agreement errors are very common, particularly in complex sentences where the subject is separated from the verb by other words or phrases. Students may mistakenly match the verb with the nearest noun rather than the actual subject. A good strategy is to first identify the core subject and then ensure that the verb matches it in number and person.

Final Answer:
The correct improvement is "describe," so the sentence should read: Affirmations are positive statements that describe a desired situation or goal and are often repeated.