Table: german_grand_prix_1951
Columns: driver
constructor
laps
time_retired
grid

Question: what is the grid when the driver is pierre levegh?
SQL: SELECT "grid" FROM german_grand_prix_1951 WHERE "driver" = 'pierre levegh'

Question: what is the grid when the laps is 2?
SQL: SELECT "grid" FROM german_grand_prix_1951 WHERE "laps" = 2

Question: what is the time/retired when the driver is toulo de graffenried?
SQL: SELECT "time_retired" FROM german_grand_prix_1951 WHERE "driver" = 'toulo de graffenried'

Question: what is the time/retired when the grid is less than 13, the constructor is alfa romeo and the laps is more than 12?
SQL: SELECT "time_retired" FROM german_grand_prix_1951 WHERE "grid" < 13 AND "constructor" = 'alfa romeo' AND "laps" > 12

Question: what is the grid when the laps is more than 20?
SQL: SELECT SUM("grid") FROM german_grand_prix_1951 WHERE "laps" > 20