How many students are on scholarship?
SELECT count ( * )  FROM Sportsinfo AS T1 JOIN Student AS T2 ON T1.StuID   =   T2.StuID WHERE T1.onscholarship   =   'Y'
students on scholarship refers to filtering records with onscholarship = 'Y'; counting students refers to COUNT(*); joining tables Sportsinfo and Student refers to JOIN operation on matching StuID.