Table: t_1981_vfl_match
Columns: home_team
home_team_score
away_team
away_team_score
venue
crowd
date

Question: What was the away team that played against Fitzroy?
SQL: SELECT "away_team" FROM t_1981_vfl_match WHERE "home_team" = 'fitzroy'

Question: On what date was the Essendon home match?
SQL: SELECT "date" FROM t_1981_vfl_match WHERE "home_team" = 'essendon'