In the following sentence improvement question, the underlined part is tone-deaf: Raja is a bad singer, he is tone-deaf. Choose the best replacement, or select No improvement if the expression is already correct.

Introduction / Context:
This sentence improvement question checks your familiarity with the idiomatic expression tone-deaf. The sentence given is Raja is a bad singer, he is tone-deaf. The underlined expression tone-deaf is used to explain why Raja is a bad singer. Your job is to decide whether this term is correct in this context or whether another option would make the sentence more appropriate. Many candidates confuse tone-deaf with other kinds of deafness, so examiners use such questions to test vocabulary and collocation.

Given Data / Assumptions:

• Sentence: Raja is a bad singer, he is tone-deaf.
• Underlined segment: tone-deaf.
• Options: stone-deaf, deaf, tune-deaf, No improvement, hard of hearing.
• Context: The sentence is describing Raja's poor singing ability and his inability to recognise musical notes correctly.

Concept / Approach:
The expression tone-deaf has a specific meaning in everyday English: it describes a person who cannot accurately perceive musical pitch. Such a person finds it difficult to sing in tune or recognise when notes are off-key. This is exactly the kind of problem that would make someone a bad singer. Therefore, tone-deaf is the correct idiomatic term here. Stone-deaf or deaf refer to a serious loss of hearing in general, not specifically to musical pitch. Tune-deaf is not a standard expression, and hard of hearing typically describes partial hearing loss, not musical insensitivity.

Step-by-Step Solution:

Verification / Alternative check:
Check the alternatives in context: Raja is a bad singer, he is stone-deaf would suggest he hears almost nothing at all, which is different from being unable to sing in tune. Raja is a bad singer, he is deaf is both harsh and inaccurate because the sentence focuses on singing ability, not general hearing. Tone-deaf, on the other hand, is frequently used in descriptions of people who cannot carry a tune. This confirms that the original phrase fits the context perfectly and should not be changed.

Why Other Options Are Wrong:
Option A (stone-deaf) is usually used for someone who is completely or almost completely deaf, not just a poor singer. Option B (deaf) again refers to general hearing loss and not specifically to musical pitch. Option C (tune-deaf) is not a standard term in English; the accepted expression is tone-deaf. Option E (hard of hearing) describes people who have some difficulty hearing, usually due to medical or age-related reasons, and is not specifically linked to poor singing. Therefore, all these alternatives miss the precise musical sense that tone-deaf carries.

Common Pitfalls:
Learners often assume that any form of deaf connected with music is appropriate, but idiomatic English is more precise. It is important to remember specific expressions like tone-deaf for musical pitch problems, colour-blind for difficulties distinguishing colours, and so on. Another pitfall is to over-correct sentences that are already idiomatically perfect. In sentence improvement questions, No improvement is sometimes intentionally the right answer, so you should always consider it seriously rather than assuming that something must be wrong.

Final Answer:
The expression is already correct, so the right choice is No improvement. The sentence should remain: Raja is a bad singer, he is tone-deaf.