The question was difficult to answer.
Here, the word "difficult" is a/ an -

• The question was difficult to answer.
Here, the word "difficult" is a/ an - Adjective.

• Here, "difficult" describes the state/ condition of the subject "The question" (meaning not easy or needing effort or skill).
- অর্থাৎ, "difficult" এখানে linking verb বা be verb "was" এর পরে বসে subject "The question" এর অবস্থা বর্ণনা করছে।
- তাই, (subject complement) হিসেবে এটি এখানে adjective হয়েছে।

• Difficult (Adjective):
- English Meaning: Not easy; needing effort or skill to do or to understand.
- Bangla Meaning: কঠিন; দুঃসাধ্য; শ্রমসাধ্য।

Source: Accessible Dictionary by Bangla Academy, Merriam & Webster Dictionary.