CREATE TABLE table_2840500_3 (player VARCHAR, nhl_team VARCHAR, position VARCHAR, nationality VARCHAR)

who is the person that plays left wing and is from canada that plays on the st. louis blues
SELECT player FROM table_2840500_3 WHERE position = "Left Wing" AND nationality = "Canada" AND nhl_team = "St. Louis Blues"
SELECT "player" FROM "table_2840500_3" WHERE "Canada" = "nationality" AND "Left Wing" = "position" AND "St. Louis Blues" = "nhl_team"