Change into indirect speech:
He said, "I have been working since morning."

• Answer: ক) He said that he had been working since morning.

- মূল বাক্যটি হলো: He said, "I have been working since morning."
- এটি একটি Present Perfect Continuous Tense - "have been working".
- Narration পরিবর্তনে Reporting Verb "said" যদি Past থাকে, তাহলে Reported Speech-এ Tense এক ধাপ Past এ চলে যায় (past perfect continuous).
- তাই have been working → had been working হয়ে যায়।
- অতএব সঠিক Indirect Speech হবে: He said that he had been working since morning.

Other options:
খ) He has been working... - Present Perfect Continuous রেখেছে, যা ভুল।

গ) He was working... - Past Continuous হয়েছে, tense পরিবর্তন ভুল।

ঘ) He worked... - Simple Past হয়েছে, ভুল tense এবং অর্থ হারায়।

Source: A Passage to the English Language, S.M. Zakir Hussain.