Because of my illness, I could not attend the picnic. (Make it Complex)

• Because of যুক্ত Simple Sentence কে Complex-এ পরিবর্তনের নিয়মঃ
- প্রথমে Simple sentence এ because of থাকলে Complex sentence এ Since/ as ব্যবহৃত হয়
- Subject বসে + Verb বসে
- Adjective /Noun বসে
- Comma বসে
- অপর বাক্যটি বসে।

Simple: Because of my illness, I could not attend the picnic.
Complex: Since I was ill, I could not attend the picnic.

• Complex sentence: 
- যে sentence এ একটি Principal clause এবং এক বা একাধিক Subordinate clause থাকে, তাকে Complex sentence বলে। 
- Complex sentence এর subordinate clause এর শুরুতে সাধারণত if, though, although, as, because, since, so that, that, until, till, unless, when, why, who, which, where, how, before, after, whether, while বসে।