not:		aren't, can't, couldn't, didn't, doesn't, don't, hadn't,
		hasn't, haven't, isn't, mustn't, shouldn't, wasn't, 
		weren't, won't, wouldn't 

  will: 	he'll, I'll, it'll, she'll, they'll, we'll

  us:		let's

  have:		I've, they've, we've, you've

  had, would:	he'd, I'd, she'd, they'd, we'd, you'd

  is, has:	he's, it's, she'd, they'd, we'd, you'd

  are:		they're, we're, you're

  am:		I'm

	I + am = I'm
	he + is = he's
	let + us = let's
	they + are = they're
	is + not = isn't
	he + will = he'll
	I + would = I'd