CREATE TABLE "semifinal_2" (
  "rank" real,
  "lane" real,
  "name" text,
  "nationality" text,
  "time" real
);

Question: Which nationality has a time of 50.92?
SQL: SELECT "nationality" FROM "semifinal_2" WHERE "time"=50.92;

Question: What is the time with fewer than 5 lanes for the United States?
SQL: SELECT SUM("time") FROM "semifinal_2" WHERE "lane"<5 AND "nationality"='united states';