Change the following sentence from Direct to Indirect speech. The trainee asked his boss, Shall I email this letter again, Sir?

Introduction / Context:
This question tests reported speech or indirect speech, particularly for polite questions with shall in the original. When converting direct speech to indirect speech, we usually change pronouns, adjust tense as needed, and often replace question word order with a statement pattern introduced by if or whether. Understanding how shall changes in indirect speech is important for accurate and natural sounding reported questions.

Given Data / Assumptions:
The direct sentence has a polite request for guidance.

Speaker: the trainee
Listener: his boss
Original words: Shall I email this letter again, Sir?
The reporting verb is asked and it already indicates politeness.

Concept / Approach:
In indirect speech, questions introduced by shall I suggesting a request for advice or permission are usually reported with should. The pronoun I in the trainee question refers to the trainee himself, so we change it to he in indirect speech. The demonstrative this generally becomes that, and we remove the question mark because the structure becomes a statement introduced by if or whether. We also do not need to repeat sir at the end because the respect is already shown by the polite reporting verb asked and the adverb politely.

Step-by-Step Solution:

Verification / Alternative check:
We can check naturalness by imagining how someone would report the conversation: The trainee asked his boss politely if he should email that letter again. This sentence reads smoothly and clearly conveys that the trainee was seeking permission or advice. It preserves the original meaning but follows the grammar rules for reported questions. A literal copy of the direct speech would not be appropriate, because indirect speech does not keep quotation marks or the original question form.

Why Other Options Are Wrong:
Option A keeps shall in the reported clause, which is not the usual transformation for this type of question; should is preferred to express advice or obligation in indirect speech. Option B repeats sir inside the reported clause, which sounds unnatural and redundant since politeness is already expressed by politely. Option C combines both issues, keeping shall and adding sir, and therefore does not follow standard rules. Option E is almost correct but changes the wording more than necessary and omits the explicit mention that the trainee asked politely; the given key prefers the more direct structure with if and should and without additional phrases like once again.

Common Pitfalls:
Many learners wrongly keep shall when reporting questions of this type or forget to change pronouns when the speaker and subject change. Some also feel they must preserve every word, including honorifics like sir, even though reported speech usually focuses on meaning rather than exact form. A helpful rule is that shall I in direct questions about advice or permission usually becomes should he or should I in reported speech, depending on the context. Applying this rule here leads directly to the correct answer.

Final Answer:
The correct indirect speech is The trainee asked his boss politely if he should email that letter again.