Additionally if your bird isn't comfortable with you he probably won't talk. For parrots talking is sort of like communication with their human flock member. So the first thing to address is your relationship with the bird.
There are a few foods that you should offer and only let him have them from your hand... I usually use grapes and almonds, but you just need to figure out what his favorite food is. Also... Greys get startled easily and if you get frustrated and move too quickly or raise your voice the Grey will just sort of retreat back into his little shell. This takes patience. Be gentle and endlessly forgiving. When you approach his cage at first try kneeling so you are not taller than the bird is high at first he won't perceive you as a threat if you are his height or slightly lower, this is only something to temporarely do until you are able to earn his trust. This helped me a lot with a stubborn, chicken little Grey I wound up with about 2 years ago. If you have any more questions you can email me if you'd like.
giraffe_gal@yahoo.com