A great game for babies from 9 months is to hide an object that he likes and then help the baby find it.
Just kidding:
Take an opaque paper bag, a purse or a backpack and put the toy the baby likes inside and help him find it by taking the toy out.
It is important for the baby to see that you have hidden the toy inside. Then you can ask, "Baby, where's the toy? And now, where is it?"
While slowly taking the toy out of the bag, say it as if it were magic words "deeeeentroooo" and when you take the toy out, say "foooraaaa".
It is from this stage of child development that the child begins to remember something that he no longer sees and this game will help him to develop more quickly at the brain level, also identifying the meaning of the words inside and outside.
Useful link:
