user: Question: What are the commissioned for Scotts, Greenock and Chieftain?
Columns: ['Name', 'Pennant', 'Builder', 'Laid Down', 'Launched', 'Commissioned', 'Fate']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Chaplet', 'R52', 'Thornycroft , Woolston', '29 April 1943', '18 July 1944', '24 August 1945', 'Sold for scrapping 1965']
SQL:

assistant: SELECT "Commissioned" FROM "Table" WHERE "Builder" = 'Scotts, Greenock' AND "Name" = 'Chieftain';