I started weaning my little girl at around the same age and found that she wasn't keen on any of the vegetables that the HV and friends had suggested (sweet potato, potato, carrot, sweed, etc). I quickly learnt though that she would eat anything as long as banana was mixed with it lol! She is now 7months and although is stillnot big on vegetables, she will eat pretty much anything else - fish, beef, chicken, pasta, rice, all types of fruit - she hasn't turned on down yet!
I would keep persevering, and eventually he will learn to take from a spoon. It does seem to take a while and then before you know it they are on three meals a day and eating you out of house and home.
As an added bonus for me my daughter began nursery at 6omnths and due to all the coughs, colds and bugs she caught she totally went off solids for 4-5weeks and I had to re-wean her twice. She started eating again two days ago though and now is eating me out of house and home, so I would say that it might take them a while to learn but once they WANT to eat, by God, they will!
Also, although I always make the food myself for my little girl I do keep a couple of jars of Hipp ruit puree in the cupboard to mix in with youghurt or custard if she is having an off food day.
If you haven't tried banana then give that a go - it's cheap, easy to prepare (mash - and hey presto!) and sweet so they seem to go for it. Then once he has the concept of taking from a spoon perhaps work other tastes in. Good luck xx