Table: mammootty_films
Columns: year
movie_title
role
direction
screenplay

Question: Which role had thulasidas direction?
SQL: SELECT "role" FROM mammootty_films WHERE "direction" = 'thulasidas'

Question: Which role did joemon play before 1991?
SQL: SELECT "role" FROM mammootty_films WHERE "year" < 1991 AND "direction" = 'joemon'