In this English grammar question on reported speech, select the correct Indirect Speech form of the warning sentence: "The teacher said to the students, 'I will not tolerate such behaviour.'"

Introduction / Context:
This problem examines how to convert a simple future warning from Direct Speech to Indirect Speech. The direct sentence is: The teacher said to the students, "I will not tolerate such behaviour." You have to decide how the future tense will not tolerate changes after a past reporting verb and how the first person pronoun I changes in reported speech.

Given Data / Assumptions:

- Reporting clause: The teacher said to the students. - Reported clause: I will not tolerate such behaviour. - Reporting verb: said, in the past tense. - The speaker is the teacher, talking about his or her own behaviour.

Concept / Approach:
In reported speech, when the reporting verb is in the past, the future tense will usually changes to would. The negative will not tolerate becomes would not tolerate. The first person pronoun I refers to the teacher, so it changes to he or she according to context. In exam questions, he is often used by default. We usually introduce the reported clause with that. Because the teacher is addressing the students, the object phrase to the students is kept in the reporting clause unchanged.

Step-by-Step Solution:

Verification / Alternative check:
To verify, you can reverse the process back into direct speech. Starting from The teacher said to the students that he would not tolerate such behaviour, you change he would not tolerate back to I will not tolerate and reintroduce quotation marks. The sentence becomes: The teacher said to the students, "I will not tolerate such behaviour." which matches the original. This confirms the indirect version is correct.

Why Other Options Are Wrong:
Option B uses the progressive form would not be tolerating, which is not appropriate here and changes the aspect unnecessarily. Option C keeps will instead of changing it to would even though the reporting verb is in the past. Option D keeps both will and the progressive form, making the tense incorrect. Option E slightly changes the meaning by adding never and again, which are not present in the original sentence. Only option A keeps the meaning intact and correctly applies the rules of tense and pronoun change in reported speech.

Common Pitfalls:
A common mistake in such questions is forgetting the tense backshift from will to would after a past reporting verb. Students sometimes also try to sound more emphatic by adding adverbs or extra words that were not in the original sentence, which is not acceptable in a strict grammar test. Another frequent error is leaving the pronoun as I instead of changing it to he or she. Always be careful to reflect the original speaker and the time reference consistently in your indirect sentence.

Final Answer:
The correct indirect speech sentence is The teacher said to the students that he would not tolerate such behaviour.