Improve the underlined part of the sentence, if necessary: "Each self is unique, and therefore cannot be compared."

Introduction / Context:
This sentence improvement question checks your understanding of correct word choice and grammar. The sentence states that each self is unique and expresses that it cannot be compared. You must decide whether this underlined phrase should be replaced to make the sentence more idiomatic and concise.

Given Data / Assumptions:
The original sentence is:

• Each self is unique, and therefore cannot be compared.

The options for the underlined part are:

• incomparable
• Non comparable
• Incomparably
• No improvement

Concept / Approach:
In English, we often use the adjective incomparable to describe something that cannot be compared because it is unique or beyond comparison. Replacing the verb phrase cannot be compared with the adjective incomparable makes the sentence more natural and elegant. The other options either have incorrect form or do not fit grammatically in the sentence.

Step-by-Step Solution:
Step 1: Understand the meaning. The sentence wants to say that each individual self is so unique that comparison is not possible. Step 2: Consider the structure Each self is unique, and therefore incomparable. Here incomparable functions as an adjective that sums up the idea that it cannot be compared. Step 3: Evaluate option incomparable. It fits grammatically after the linking verb is and agrees with the idea of uniqueness. Step 4: Evaluate Non comparable. As given, it should be written as non comparable or preferably non comparable with a hyphen, but this phrase is less idiomatic than incomparable. Step 5: Evaluate Incomparably. This is an adverb and cannot substitute for the predicate adjective position after is in the sentence. Step 6: Evaluate No improvement. The original phrase cannot be compared is understandable, but the single word incomparable is more precise and stylistically better. Step 7: Therefore, incomparable is the most appropriate improvement.

Verification / Alternative check:
Read the improved sentence: Each self is unique, and therefore incomparable. This version is grammatically correct and sounds natural in formal English. The meaning clearly indicates that each self is beyond comparison. If we used non comparable, the phrase would look awkward and less standard. The adverb incomparably would require a different structure, such as Each self is incomparably unique, which is not what the question offers.

Why Other Options Are Wrong:
Non comparable is wrong because it is not the usual adjective used in this philosophical or reflective context, and its spelling and spacing also create minor issues. Incomparably is wrong because it is an adverb and does not fit the pattern is incomparably in this sentence without additional wording. No improvement is wrong because the sentence can be made more concise and idiomatic by using the single adjective incomparable instead of the phrase cannot be compared.

Common Pitfalls:
Some students choose No improvement because the original sentence is understandable. However, sentence improvement questions often look for more natural and elegant options rather than simply grammatical correctness. Another pitfall is confusion between adjective and adverb forms, as in incomparable versus incomparably. Remember to match the grammatical role in the sentence: after the verb is, we usually need an adjective, not an adverb.

Final Answer:
The correct improvement is incomparable.