Dear, I can understand your concerns. Is there a history of delayed milestone development? Did he start late to walk? At what age did he started babbling, talking? We need to consider if the problem is specific to learning or it is global. If there is any intellectual disability, a timely training and intervention can help improving the functioning. However, it requires a detailed history work up to establish a condition or diagnosis.
Next Steps
Seriously consider to consult a psychiatrist.