Make it simple: As soon as the thief saw the police, he ran away.

• Complex to simple,

• Complex Sentence এ ‍as soon as থাকলে
- Simple Sentence এ as soon as এর পরিবর্তে on/ at the very moment of (সাথে সাথেই) বসে।
- On + Verb + ing Or, At the very moment of + Verb + ing
- এরপর as soon as যুক্ত clause এর বাকি অংশ বসে।
- প্রথম subject টি দ্বিতীয় clause এর subject হিসাবে বসে, এবং দ্বিতীয় clause এর বাকি অংশ বসে।

Complex: As soon as the thief saw the police, he ran away.
Simple: At the very moment of seeing the police, the thief ran away.

Or
Simple: On seeing the police, the thief ran away.