When did canada become a completely independent country?
No context provided
When did Canada become a self governing country, even though Britain could make changes to the constitution?
1931
No context provided
When did Canada adopt its own constitution?
1982
Canada Act 1982
https://en.wikipedia.org/wiki/Canada%20Act%201982
The Canada Act 1982 (1982 c. 11; French: Loi de 1982 sur le Canada) is an act of the Parliament of the United Kingdom and one of the enactments which make up the Constitution of Canada. It was enacted at the request of the Senate and House of Commons of Canada to patriate Canada's Constitution, ending the power of the British Parliament to amend the Constitution. 
Canada Act 1982
In 1931, Canada became a self governing country, but Britain could still make changes to their constitution. The Canada Act 1982 was enacted at the request of the Senate and House of Commons of Canada to patriate Canada's Constitution, ending the power of the British Parliament to amend the Constitution. 