In this English error spotting question, identify which part of the sentence is incorrect in: "I shall go (A) by the (B) 3 o' clock's train. (C) No error (D)".

Introduction / Context:
This question focuses on the correct way to refer to a scheduled train in English, especially the phrase involving "o'clock". The sentence is: "I shall go (A) by the (B) 3 o' clock's train. (C) No error (D)". You must identify which part contains the grammatical or idiomatic error and understand the correct standard expression.

Given Data / Assumptions:

• Full sentence: "I shall go by the 3 o'clock's train."
• Part (A): "I shall go"
• Part (B): "by the"
• Part (C): "3 o' clock's train."
• Part (D): "No error"
• The speaker wants to say that they will travel on the train that leaves at 3 o'clock.

Concept / Approach:
In English, the standard way to refer to a scheduled train is to say "the 3 o'clock train", not "the 3 o'clock's train". The construction "o'clock" is already a fixed time expression and does not normally take a possessive 's in this context. We often say "the 3 o'clock show", "the 10 o'clock news", or "the 6 o'clock flight". Adding another genitive 's after "o'clock" is incorrect and unidiomatic. Therefore, part (C) contains the error and should be corrected.

Step-by-Step Solution:
Step 1: Read the sentence focusing on "3 o' clock's train".Step 2: Recall common English expressions: "the 3 o'clock train", "the 4 o'clock bus", etc., which do not use the possessive 's after "o'clock".Step 3: Remove the incorrect possessive and rewrite the phrase as "the 3 o'clock train".Step 4: Check parts (A) and (B). "I shall go" correctly uses "shall" to talk about the speaker's future plan, and "by the" is a suitable prepositional phrase before "3 o'clock train".Step 5: Conclude that only part (C) is wrong and needs correction.

Verification / Alternative check:
With the correction, the full sentence becomes: "I shall go by the 3 o'clock train." This is a standard way to speak about catching a particular train. If we tried to justify "3 o'clock's train", it would sound awkward and unnatural because we do not normally express possession between the time expression and the vehicle in this way. Similarly, we say "the five o'clock meeting", not "the five o'clock's meeting".

Why Other Options Are Wrong:

• Option A (part A "I shall go") is grammatically acceptable, especially in formal or British English for future intention.
• Option B (part B "by the") is the correct preposition for means of travel in this context, as in "go by the bus", "go by the train".
• Option D (No error) cannot be chosen because the phrase in part (C) clearly deviates from standard usage.

Common Pitfalls:
Some learners overgeneralise the possessive 's, assuming it can be attached to any noun phrase to indicate association. However, fixed time expressions like "three o'clock" are best left without an additional possessive when they simply label events or services, such as trains and TV programmes. Remembering standard collocations like "ten o'clock train", "nine o'clock news", and "seven o'clock movie" will help you avoid this error in exams.

Final Answer:
The incorrect part is C; the phrase should be "the 3 o'clock train", not "the 3 o'clock's train".