If it's cognitive, may I suggest the Pre school prep video line. I have a 3 year old that couldn't grasp colours 3weeks watching this video 20 minutes a day she knows her colours perfectly. My DD learned her upper and lower case letters from it. My now daycare group of 2 year olds are learning there sight words. I have a 2 year old that can say 90% of sight words with flash cards.
Check to see if you can get any at the library. I bought mine of amazon.ca.


http://www.preschoolprepco.com/