In this English error-spotting question, identify the part of the sentence which contains the pronoun error: "The two men were(1) quarrelling with one another(2) claiming the same watch as their own.(3) No Error(4)".

Introduction / Context:
This question tests your understanding of reciprocal pronouns in English, specifically the correct use of "each other" and "one another". The sentence is: "The two men were quarrelling with one another claiming the same watch as their own." You are asked to find which part of the sentence contains a grammatical error. Such questions are common in competitive exams to check how accurately you use pronouns according to the number of people involved.

Given Data / Assumptions:

• The sentence is divided into four parts: (1) The two men were, (2) quarrelling with one another, (3) claiming the same watch as their own, (4) No Error.
• The subject is clearly "The two men", which refers to exactly two persons.
• The phrase "quarrelling with one another" uses a reciprocal pronoun.
• We must identify any mismatch between the number of persons and the pronoun chosen.

Concept / Approach:
In traditional grammar, "each other" is typically used when referring to two persons or things, while "one another" is used when referring to more than two. Although modern usage sometimes blurs this distinction, competitive exam questions usually follow the traditional rule very strictly. Since we are talking about exactly two men, the correct reciprocal pronoun should be "each other", not "one another". Therefore, the error lies in the part that uses "one another".

Step-by-Step Solution:
Step 1: Identify the subject: "The two men" clearly indicates that only two people are involved. Step 2: Note that they are "quarrelling with one another", which is the reciprocal pronoun phrase. Step 3: Recall the rule: use "each other" for two persons and "one another" for more than two persons in formal grammar. Step 4: Recognize that because the sentence speaks about "two men", the pronoun should be "each other". Step 5: Check parts (1) and (3) for other possible errors and see that they are grammatically fine. Step 6: Conclude that part (2) contains the error and should be corrected to "quarrelling with each other".

Verification / Alternative check:
You can test the rule with other examples: "The two friends hugged each other" is the standard form, not "hugged one another". When referring to a group, such as "The players congratulated one another", we naturally use "one another" because more than two people are involved. Applying this pattern to the given sentence confirms that "each other" is the appropriate choice for two men, and therefore the phrase "quarrelling with one another" is incorrect in the strict exam sense.

Why Other Options Are Wrong:
Part (1) "The two men were" correctly introduces the subject and verb; there is no agreement error. Part (3) "claiming the same watch as their own" is grammatically correct, as "their own" appropriately refers back to "the two men". Part (4) represents the option "No Error", but we have already identified a genuine error in part (2), so option 4 cannot be correct.

Common Pitfalls:
Many learners have seen modern usage where "each other" and "one another" are used interchangeably, leading them to wrongly select "No Error". However, competitive examinations usually expect candidates to follow the traditional rule strictly. Another pitfall is focusing on less important phrases like "claiming the same watch as their own" while ignoring the pronoun rule. To do well on such questions, always scan for standard textbook rules about pronouns, prepositions, and comparisons.

Final Answer:
The error is in part 2, so option "2" is the correct choice. The corrected sentence should read: "The two men were quarrelling with each other, claiming the same watch as their own."