CREATE TABLE "knockout_stages" (
  "home_1st_leg" text,
  "home_2nd_leg" text,
  "1st_leg" text,
  "2nd_leg" text,
  "aggregate" text
);

Question: What is the aggregate when the second leg is 1-3?
SQL: SELECT "aggregate" FROM "knockout_stages" WHERE "2nd_leg"='1-3';

Question: For home of River Plate, what is the first leg listed?
SQL: SELECT "1st_leg" FROM "knockout_stages" WHERE "home_2nd_leg"='River Plate';

Question: With an aggregate of 0-2, what is listed for home?
SQL: SELECT "home_2nd_leg" FROM "knockout_stages" WHERE "aggregate"='0-2';

Question: If the home is Atlético Tucumán, what is the name of the first leg?
SQL: SELECT "1st_leg" FROM "knockout_stages" WHERE "home_2nd_leg"='Atlético Tucumán';

Question: If second leg is Newell's Old Boys, what name is first leg?
SQL: SELECT "1st_leg" FROM "knockout_stages" WHERE "home_2nd_leg"='Newell''s Old Boys';