I'm still trying to work out how I managed to leave a couple of garlic plants unharvested last year (spuds, easy, garlic, potential Specsavers!)
You certainly can eat the leaves, which will have a garlic flavour but not as strong as the cloves.
I'm going to leave mine to grow just to see what happens - each clove is clearly producing its own shoot, but whether I get a cluster of usable bulbs or a random mess remains to be seen (not holding my breath!)