"He must respect his elders." [Make it Negative]

Answer: He can not but respect his elders.

→ Affirmative Sentence-এ "must" থাকলে Negative করার সময় "can not but" বা "can not help + verb-ing" ব্যবহৃত হয়। তবে "can not but" ব্যবহারের ক্ষেত্রে verb-এর base form অপরিবর্তিত থাকে।
→ Structure: can not but + base form of verb.

উল্লিখিত প্রশ্নে দেওয়া বাক্য: "He must respect his elders."
এখানে "must" রয়েছে, তাই Negative করার সময় "can not but" ব্যবহার করব এবং "respect" (verb-এর base form) অপরিবর্তিত থাকবে।
→ অর্থাৎ Rule অনুসারে Correct Negative Sentence: "He can not but respect his elders."

Example:
Affirmative: We must obey our teachers.
Negative: We can not but obey our teachers.
Affirmative: He must tell the truth.
Negative: He can not but tell the truth.
Affirmative: You must laugh at the joke.
Negative: You can not help laughing at the joke.
Affirmative: She must cry at her failure.
Negative: She can not help crying at her failure.