The comparative form of: The Padma is the longest river in Bangladesh.

- Superlative Degree: The Padma is the longest river in Bangladesh.
- Comparative Degree: The Padma is longer than any other river in Bangladesh.

• শুধু 'the' যুক্ত Superlative Degree কে Comparative Degree তে রূপান্তরের নিয়ম:
- প্রদত্ত Sentence এর Subject ও verb বসে।
- the উঠে যায়।
- Superlative এর Comparative form বসে।
- than any other/than all other বসে।
- প্রদত্ত Sentence এর বাকি অংশ বসে।

• Note: of all থাকলে সেক্ষেত্রে of all এর জায়গায় than all other বসে এবং of any এর পরিবর্তে than any other বসে।

More examples:
Superlative Degree: Messi is the best footballer we have ever seen.
Comparative Degree: Messi is better than any other footballer we have ever seen.

Source: Advanced Learner's Communicative English Grammar & Composition By Chowdhury & Hossain.