Sentence completion:
If I had known you were coming, ______________________.

If I had known you were coming, I would have gone to the station. 
বাংলা অনুবাদ = আমি যদি জানতাম তুমি আসবে, তাহলে আমি ষ্টেশনে থাকতাম। 

Third conditional sentence এ if যুক্ত clause টি যদি past perfect tense হয়, তাহলে ফলাফল এর clause টি হবে subject + would have + verb এর past participle form + object. 

Reference: Essential Grammar in Use, Raymond Murphy