In this English error spotting question, read the sentence "Freedom fighters laboured (1) / to the good of (2) / the poor enslaved masses. (3) / No Error (4)" and identify which part of the sentence contains a grammatical or idiomatic error.

Introduction / Context:
This is an English grammar error spotting question. The sentence is divided into parts labelled (1), (2), (3) and (4). You must decide which part, if any, contains an error in usage or idiom. The sentence is: "Freedom fighters laboured (1) / to the good of (2) / the poor enslaved masses. (3) / No Error (4)". Such questions test your familiarity with standard English expressions and preposition usage.

Given Data / Assumptions:

• Part (1): "Freedom fighters laboured"
• Part (2): "to the good of"
• Part (3): "the poor enslaved masses."
• Part (4): "No Error"
• The intended meaning is that freedom fighters worked hard for the benefit of the poor enslaved masses.

Concept / Approach:
To solve error spotting questions, look for collocations and prepositions commonly used with certain verbs. The verb "labour" in this sense means "work hard" and is normally followed by "for" when you talk about the cause or goal: "labour for the good of humanity", "labour for justice". The phrase "to the good of" is not idiomatic after "laboured". Instead, the standard expression is "laboured for the good of". Therefore, the error lies in part (2), where the preposition "to" should be replaced with "for".

Step-by-Step Solution:
Step 1: Read the entire sentence: "Freedom fighters laboured to the good of the poor enslaved masses."Step 2: Understand the meaning: freedom fighters worked hard so that the poor enslaved masses would benefit.Step 3: Recall the usual pattern "labour for something", for example, "laboured for the freedom of their country".Step 4: Recognise that "to the good of" sounds unnatural and unidiomatic following "laboured".Step 5: Conclude that part (2) contains the error and should read "for the good of" instead of "to the good of".

Verification / Alternative check:
Replace the incorrect phrase with the correct collocation and read the sentence again: "Freedom fighters laboured for the good of the poor enslaved masses." This version is grammatically correct and idiomatic, and it clearly expresses the intended meaning. The other parts of the sentence ("Freedom fighters laboured", "the poor enslaved masses") are grammatically sound as they stand. Therefore, only part (2) needs correction.

Why Other Options Are Wrong:
Part (1) correctly uses "Freedom fighters laboured", with a plural subject and past tense verb. Part (3) describes "the poor enslaved masses", which is grammatically acceptable as a noun phrase. Part (4), "No Error", is wrong because we have identified a clear error in part (2). Hence, these parts do not require any change, and they cannot be the correct answer to the question.

Common Pitfalls:
Many students focus too much on the more complicated noun phrase "poor enslaved masses" and suspect it to be wrong, while the real problem is the preposition "to". Another pitfall is overthinking "laboured" and trying to replace it with synonyms like "worked", even though "laboured" is acceptable. Always check verb preposition combinations, as incorrect prepositions are a favourite testing area in competitive exams.

Final Answer:
The error is in Part (2), because the correct idiomatic expression is "laboured for the good of the poor enslaved masses", not "laboured to the good of".