Zoo is very strong in spelling so we do not do traditional spelling exercises. We get at spelling through reading and vocabulary development (greek and latin affixes). We used some lists of commonly mispelled words to raise his awareness of mispellings.
The University of Hull50 Common ErrorsWriting Tutorial ServiceCommon Errors in EnglishCommon contextual errors are trickier for Zoo.
White SmokePracticing homophonesWe also look at variations between Canadian, British and American spellings.
http://www.clcplus.cstdi.gov.hk/images/upload/ENet/Common%20Errors%20and%20Guidelines%20for%20Spelling.htm