A very small percentage of children may have a medical disability. But there are common reasons why a child of normal ability may not begin to talk by age two. Both of her children were late talkers and very slow to learn to read. There is no pressure. You are not pushing your child.
Children love to learn new things.
Children have little trouble learning that the letter has a name and it says something. Put corn meal or grits in a cookie sheet with sides. Guide his finger to draw the letters. Some children will try to use a pencil at age 2 or 3, others are not physically mature enough. You just say it yourself and move on to whatever else you are doing.