In this English grammar error-spotting question, identify the part of the sentence that contains an error in "He learnt the alphabets at the age of four."

Introduction / Context:
This question tests your understanding of correct noun usage in English, particularly with the word alphabet. The sentence He learnt the alphabets at the age of four is split into parts, and you need to find which part is grammatically incorrect. Such questions are common in competitive exams to check fine points of standard usage.

Given Data / Assumptions:
The sentence is divided as:

• Part A: He learnt
• Part B: the alphabets
• Part C: at the age of four.
• Part D: No Error

We assume a neutral context in which a child is learning letters of a language.

Concept / Approach:
In standard English, when we refer to the complete set of letters in a language (like A to Z in English), we usually use the singular noun alphabet, not alphabets. The plural alphabets is used only when talking about the writing systems of different languages together, for example Indian scripts use many alphabets. Here, the sentence clearly refers to the letters of one language that a child learns, so the singular form the alphabet should be used.

Step-by-Step Solution:
Step 1: Examine Part A, He learnt. The verb learnt is the past tense of learn and is correct in British usage. Step 2: Examine Part B, the alphabets. In this context the child is learning the basic letters of one language. Therefore, we should use the singular form the alphabet. Step 3: Examine Part C, at the age of four. This phrase correctly indicates the time when the learning took place. Step 4: Combine the corrected elements: He learnt the alphabet at the age of four. This sentence is grammatically correct and natural. Step 5: Therefore, the error lies in Part B, where alphabets should be replaced with alphabet.

Verification / Alternative check:
We can cross-check by considering general descriptions: Children usually learn the alphabet in kindergarten. Here, nobody says the alphabets unless they are referring to several different languages, such as He is studying the alphabets of five different languages. In the question, it is clearly about one child and a single language, so the singular form is correct.

Why Other Options Are Wrong:
Part A is correct because He learnt is an acceptable past tense form. Part C is also correct and does not contain any grammatical or idiomatic error. Part D, No Error, is wrong because there is a clear mistake in Part B. Hence the only problematic part is the phrase the alphabets.

Common Pitfalls:
Learners sometimes assume that because there are many letters, the noun must be plural. However, alphabet denotes the entire set as a single unit. Similar patterns appear in words like furniture or luggage, which remain singular collective nouns. Remembering that we say learn the alphabet when referring to the basic letters of one language will help avoid this repeated mistake.

Final Answer:
The incorrect part is B (the alphabets); it should be the alphabet.