English Grammar — Error Spotting (Prepositions with 'introduce') Identify the part that contains a grammatical error. If there is no error, choose 'No error'. Full sentence: Rajdeep always introduces himself by his first name and never mentions his family name.

Introduction / Context:
The focus here is prepositional choice with "introduce." The usual and idiomatic phrasing is "introduce oneself with one's first name" or simply "introduce oneself as X." Using "by" can sound unnatural or ambiguous in this context.

Given Data / Assumptions:

• Sentence: "Rajdeep always introduces himself by his first name and never mentions his family name."
• We must locate the fragment that is non-idiomatic.

Concept / Approach:

With "introduce," preferred collocations are "introduce (oneself) as ..." or "introduce (oneself) with (one's) first name." The phrase "by his" after "introduces himself" is not standard in this sense.

Step-by-Step Solution:

1) Examine the verb + preposition pairing in B.2) Replace "by" with "with" or use "as": "introduces himself with his first name" / "introduces himself as Rajdeep."3) Other parts are acceptable.4) Conclude B is the error.

Verification / Alternative check:

Corrected: "Rajdeep always introduces himself with his first name and never mentions his family name." This is idiomatic.

Why Other Options Are Wrong:

A: Grammatically fine subject and verb.C: Completes the coordinated predicate correctly.D: Noun phrase "his family name" is fine.E: Not valid because B is wrong.

Common Pitfalls:

Literal translation from other languages may default to "by" for method/instrument; English idiom varies by verb, so collocations must be learned case-by-case.

Final Answer:

himself by his