How many matches were played on May 2008?
in May 2008 refers to SUBSTR(Match_Date, 1, 4) = '2008' AND SUBSTR(Match_Date, 7, 1) = '5'
SELECT SUM(CASE WHEN SUBSTR(Match_Date, 7, 1) = '5' THEN 1 ELSE 0 END) FROM `Match` WHERE SUBSTR(Match_Date, 1, 4) = '2008'