My first dog (not a yorkie) was 10 years old when i adopted her and had been abused. She never knew how to play and lick, and was frightened when i threw a ball for her. After about 8 months, she did start to run happily around the garden with me, but never really played. The saddest thing was that she never ever wagged her tail properly. Occasionally it would start to wag, but she stopped it straight away, looking fearful of what might happen...it broke my heart to think what she had been through. I eventually gained her trust enough for her to come and have lots of big hugs, and she used to nuzzle into my neck and almost purr in my ear! Its nearly 2 years since i lost her to heart disease, but theres never a day i dont think about her and am so glad that i gave her an endless supply of love in her twilight years. Im sure your little man will come round eventually, but be patient, as it might take a long time. When it happens it will light up your day.