How do I opt-out of the Social Security system and give up my Social Security Number? If I do this, am I then exempt from paying Social Security income tax?


Question: Past perfect sentence in "I would have killed the snake if I had hit him..."
Answer: Yes, it is. It's the third conditional, where you talk about an action in the past that didn't take place. Aside from that, you are missing the or a in your sentence.


  I would have killed the snake if I had hit him hard with the or a stick.