CREATE TABLE table_6340 ("Name" TEXT, "Circuit" TEXT, "Date" TEXT, "Winning driver" TEXT, "Winning constructor" TEXT, "Report" TEXT)

Who is Winning driver on 18 may?
SELECT "Winning driver" FROM table_6340 WHERE "Date" = '18 may'
SELECT "Winning driver" FROM "table_6340" WHERE "Date" = '18 may'