If you would correct my sentence fragment...

I have noticed that I have the tendency to say a lot of sentence fragments starting with "if" in place of asking questions or making direct requests.  For example:

• What I say: "If someone could pass me the butter."
  Proper English: "Could someone please pass me the butter?"
• What I say: "If you guys would do your homework."
  Proper English: "You guys should do your homework."

I noticed that lots of people speak like this.