Re: difference between american and english
I wonder if you mean "got" and not "get."
My American view:
Have you got a pen? -- More likely to be used when you want to borrow it.
Do you have a pen? -- More likely to be used when a pen is needed. You'll have to fill out this form in blue or black in. Do you have a pen? No? You can borrow mine. However, I may be just as likely to use this when I want to borrow your pen too. Do you have a pen I could use for a moment?
I've got a pen. I have a pen. -- Either one could be used, but you're more likely to echo the tense used by the person who asked.
While "got" is the past of get, it means "to obtain" not "to have."
"Got" is its own word as well.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.