In the following question, some part of the sentence may have an error. Identify the part that contains the error, if any: “I am vexed at him (1) for what all he has (2) done for him till date. (3) No error (4)”

Introduction / Context:
This question is from the common error spotting pattern where a sentence is divided into numbered parts. The task is to find the segment that contains a grammatical or usage error. The given sentence describes someone being vexed or annoyed with another person because of what that person has done. One of the parts has a pronoun usage problem, and we must locate and correct it.

Given Data / Assumptions:

• Complete sentence: “I am vexed at him (1) for what all he has (2) done for him till date. (3) No error (4)”
• Part 1: “I am vexed at him”
• Part 2: “for what all he has”
• Part 3: “done for him till date.”
• We assume the intended meaning is that the speaker is vexed with someone because of what that person has done for the speaker.

Concept / Approach:
The main error lies in the pronoun in part 3: “done for him till date”. Given the context, the correct phrase should be “done for me” because it is the speaker who is affected by the actions. If the sentence is saying “I am vexed with him for what all he has done for him”, it creates confusion and illogical repetition. The second “him” is wrong and should be replaced by “me”. While part 1 could also be improved by changing “vexed at him” to “vexed with him”, examination keys usually focus on the clear pronoun mismatch in the third segment as the primary tested error.

Step-by-Step Solution:

Verification / Alternative check:
Rewrite the sentence in a corrected form: “I am vexed with him for all that he has done for me till date.” This version makes good sense: the speaker is irritated with someone because of that person actions towards the speaker. If we keep “him” in part 3, the sentence would mean that the person has done many things for himself, and yet the speaker is vexed, which especially with “for what all he has done for him” is logically confusing and not natural. Hence, part 3 contains the error. Even if we also improve “vexed at him” to “vexed with him” in practical usage, exam wise the pronoun in part 3 is the clearest mistake to be identified.

Why Other Options Are Not Marked as the Main Error:

• Option A (part 1): “vexed at him” could be replaced with “vexed with him” for more idiomatic English, but “vexed at” is not strictly wrong and is sometimes found in older usage. Exam patterns usually reserve the correction for a more definite error.
• Option B (part 2): “for what all he has” is informal but understandable and not clearly ungrammatical in the way that the pronoun mismatch is.
• Option D (part 4): “No error” is incorrect because we have clearly found a mistake in part 3.

Common Pitfalls:
Error spotting questions often contain informal expressions that may or may not be corrected, which can distract candidates from more definite mistakes. A common pitfall is to over focus on stylistic improvements instead of grammar and logic. In this question, some candidates might quickly mark part 1 because they remember that “vexed with” is preferred. However, exam setters typically choose one clear error that changes meaning, such as a wrong pronoun. A good strategy is to first look for errors that make the sentence structurally or logically incorrect and only then consider more subtle collocational issues.

Final Answer:
The error is in part 3, where “for him” should be “for me”.