In this counseling answer:
•I would kindly suggest you start with age-appropriate teaching when the child is able to put words together in sentences.
•While the child may not be developmentally able to grasp the full meaning, in time the Qur’an will become something that is easily read and understood by the child as she or he matures.
While I am not an Islamic scholar, I do advise parents to read the Qur’an to their children from the day they are born. The spiritual food and nourishment which even an infant can receive from the Qur’an is amazing.
If a child hears the Qur’an being recited from birth, hey will develop a natural familiarity and love for our most Holy book. As a child learns to speak and then read, include the Qur’an as a learning modality.
The child having heard the Qur’an being read to them from birth, will feel an affinity for the Qur’an thus making the actual learning and reading of the Qur’an much easier.
It will feel natural. As far as a specific age, each child differs in their growth and learning abilities. I would kindly suggest you start with age-appropriate teaching when the child is able to put words together in sentences.
Scholars may have different views so you may want to consult with a scholar, however, I feel if a child can put sentences together, what better way to increase their skills than by introducing the Qur’an as a reading book.
While the child may not be developmentally able to grasp the full meaning, in time the Qur’an will become something that is easily read and understood by the child as she or he matures.
As far as when a child should start school, countries and states have different laws/rules pertaining to when a child is mandated to go to school. If this is not the case in your country, then the option is really up to you. Usually, formal schooling starts around the age of 5 or 6 years of age.
Preschools are another option some parents chose if the child is young (around 2.5-4years old). In preschools children usually, thrive and learn skill sets that prepare them for further study.
If you are thinking of preschool, it will depend on when you feel your child is emotionally ready to be away from home, their level of maturity (level of independence), their ability to use the potty, and their social skills.
Children who attend preschools usually do not go for a full day but start out with a few hours a day for social development, creativity and fun activities.
If you decide preschool is not for your child, you can always supplement their learning by providing creative and social activities at home, preferably with other children to increase social skills as well.
We wish you the best, may Allah bless your endeavors.
Disclaimer: The conceptualization and recommendations stated in this response are very general and purely based on the limited information provided in the question. In no event shall AboutIslam, its counselors or employees be held liable for any damages that may arise from your decision in the use of our services.