In the following sentence, a part is underlined and numbered. Identify the part of the sentence that contains an error and select the correct option. If the sentence is free from error, select 'No error'. His assistance (1) / was not happy (2) / with his job. (3) / No error (4)

Introduction / Context:
This question is an example of an error spotting item in English grammar, a very common type in competitive exams. The learner must read the full sentence, divide it into the labelled parts, and identify which segment contains a grammatical or lexical error. Here, the sentence looks almost correct in terms of structure and verb agreement, so the error lies in vocabulary choice, specifically in the misuse of a noun that looks similar to the intended word.

Given Data / Assumptions:

• The sentence is: "His assistance (1) / was not happy (2) / with his job. (3) / No error (4)".
• Part (1) uses the word "assistance".
• The intended meaning is to talk about a person who works for him.
• The other parts of the sentence are grammatically sound: "was not happy" and "with his job" are correct.
• We assume standard formal English usage as required in exams.

Concept / Approach:
The main concept tested is the difference between two similar looking nouns: "assistant" and "assistance". "Assistant" is a person who helps someone, often in a job role. "Assistance" is the noun form meaning "help" or "support", and it is not used as a person. In error spotting questions, exam setters often choose such confusing pairs to examine whether candidates truly understand the vocabulary. The correct approach is to evaluate the meaning of the sentence rather than only checking grammar and tense.

Step-by-Step Solution:
Step 1: Read the entire sentence: "His assistance was not happy with his job." Step 2: Ask what the sentence is trying to convey. The idea is that a person who works for him is unhappy with the job. Step 3: Note that "assistance" means help or support, which is not a person and cannot logically be happy or unhappy. Step 4: The correct word for a person working under someone is "assistant". Therefore the sentence should read: "His assistant was not happy with his job." Step 5: Parts (2) and (3) are grammatically fine: "was not happy" is correct verb usage and "with his job" is a proper prepositional phrase. Step 6: Hence, the error lies in part (1), and the correct answer is option 1.

Verification / Alternative check:
To verify, try replacing "assistance" with "help" and read the sentence: "His help was not happy with his job." This sounds odd because "help" used as a noun here refers to the act of helping, not a person. On the other hand, replacing it with "assistant" gives "His assistant was not happy with his job," which is perfectly natural and widely used in everyday English. This confirms that the only error is in word choice in part (1).

Why Other Options Are Wrong:
Option 2: "was not happy" is a correct verb phrase for a singular subject like "assistant". The tense and agreement are both correct. Option 3: "with his job" is the right prepositional phrase to express dissatisfaction related to employment. There is no grammatical issue here. Option 4: "No error" is incorrect because we have clearly seen that the word in part (1) is wrong and must be changed.

Common Pitfalls:
A typical mistake is to scan only for tense or article errors and ignore vocabulary. Many students focus so hard on verbs and prepositions that they read the word "assistance" quickly and assume it is correct because it looks sophisticated. Others may be confused by the fact that in some informal uses "the help" can refer to staff, but this is not the standard expected in formal exam English. Learners should always check whether the noun used actually denotes a person or an action, especially when context clearly talks about a human subject with feelings like happiness or dissatisfaction.

Final Answer:
The error is in part 1, because the sentence should use "assistant" instead of "assistance".