Just teach him repeatedly, I buy a lot of magnetic A B C and 1-10, and magnetic shapes and a white board for him, he will continue to stick it and remove it and tell one by one, and i always ask him the shape and color whenever i see that at home, and in the street, you will soon discover that they are very creative, for example, when i sit with butterfly leg, he will immediately recognise there is a triangle between my leg, they can even tell the difference between oval and circle, octagon, square and diamond, etc...at this age, they can really memorise lot of things.
曬下先..阿仔A-Z 大細階, Color: red, green, blue, yellow, purple, orange, peach, pink, black, white, brown, shape: circle, triangle, square, rectangle, oval, diamond, etc all can recognize and tell ...but only in english, number 1-10, but only in english...may be english is easier for them ar.