user: Question: Which Outcome has an Opponent of Wendy Turnbull, and a Surface of Grass?
Columns: ['Outcome', 'Date', 'Tournament', 'Surface', 'Opponent', 'Score']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Winner', '14 May 1973', 'Guildford', 'Clay', 'Kazuko Sawamatsu', '7–5, 4–6, 6–3']
SQL:

assistant: SELECT "Outcome" FROM "Table" WHERE "Opponent" = 'Wendy Turnbull' AND "Surface" = 'Grass';