When you see that your bird is standing on one foot, then you know that he is relaxed. Greys talk to each other , it appears , through a series of clicks, beeps and similar sounds. If you hear him making what sounds like he is grinding his beak together, this is a happy sound and once again the bird is relaxed. My grey makes a very loud single scream if she is mad or alarmed and if she is mildly nervous she does not talk at all either in bird or in human speech, she remains very quiet.
Earlier in one of your posts you mentioned looking for information on what to feed your Grey, did you find a listing of safe and toxic foods? If you did not then please check out this link
viewtopic.php?f=8&t=12521 The list starts on the second page of the post and it not only covers foods but plants and trees and some household items that you should know about. This list has helped me a lot over the past few years with keeping my birds safe and happy.
Parrots love to share our food and as a general rule they want their share of anything they see us eating. Not only is eating a social event for a parrot it is also a bonding activity. Because of this and the way that parent birds teach their young what foods to eat in the wild, you can use this as a means of teaching your bird to eat a much wider variety of foods. While pomegranates are good for your parrot, he need many more types of fruits and vegetables in his diet or he is going to get sick. Try such foods as raw broccoli, carrots, green beans, apples, mangos, cantelope, squash corn on the cob to name just a few things that you can feed to your parrot.
Try cutting some of these foods up into small pieces and then sit down with your bird and talk to him while you nibble on one or two of these foods. Make happy and yummy type of noises while you nibble on these foods, but do not offer any of them to your bird. You want him to see you eating them and you want him to hear how great and wonderful tasting these foods are and then you want him to think that they are so very special that you intend to eat them all by yourself. He will watch you eating them and then he will begin to ask you to give him some of these foods. Do not offer him any of these new foods. Keep talking to him and making happy noises while you keep nibbling on them. He will get louder and more insistent that you share this food with him, he will begin to demand that you share this wonderful food with him, but do not offer him these foods. What you want to do is to have the dish that you are eating from placed so that you can make it easy for him to steal a piece of the food. Protect the food from him just a little as you want him to work a little bit to steal some of it. Don't be too protective of it as you really want him to try it but you want him to work at it just a little. This is what the parent parrots do to get their young to eat the right foods, and it can work for you as well.
It is very likely that when he steals a piece of this food that he will spit it out instead of eating it right at first, this is normal, parrots are messy eaters at best and waste a lot of food that they could eat. When he has stolen a piece or two of the new food, leave the rest of it in his normal eating place for him to try later on. There is no way of knowing how long it will take for them to eat this food but be patient and keep trying this with a variety of different foods and he will start eating them. some faster than others but eventually he will begin to eat many of them.