CREATE TABLE "singles_5" (
  "date" text,
  "tournament" text,
  "surface" text,
  "opponent" text,
  "score" text
);

Question: Which opponent was on July 21, 2008?
SQL: SELECT "opponent" FROM "singles_5" WHERE "date"='july 21, 2008';

Question: What was the date of the tournament with a clay surface and an opponent of Irina Falconi?
SQL: SELECT "date" FROM "singles_5" WHERE "surface"='clay' AND "opponent"='irina falconi';

Question: Who was the opponent on May 10, 2009?
SQL: SELECT "opponent" FROM "singles_5" WHERE "date"='may 10, 2009';