CREATE TABLE "classification" (
  "driver" text,
  "constructor" text,
  "laps" real,
  "time_retired" text,
  "grid" real
);

Question: What is the average grid number for cars that retired due to engine failure before 18 laps?
SQL: SELECT AVG("grid") FROM "classification" WHERE "time_retired"='engine' AND "laps"<18;

Question: What is the time/retired for jo siffert with a grid under 11?
SQL: SELECT "time_retired" FROM "classification" WHERE "grid"<11 AND "driver"='jo siffert';

Question: What driver has under 19 laps and a grid under 10?
SQL: SELECT "driver" FROM "classification" WHERE "laps"<19 AND "grid"<10;