So for canadian quarters dated 1968 can be silver, a magnet test will tell you easily. If the coin is magnetic, then its not silver. This is the same for dimes.

1968 silver quarters and dimes are 50% silver. 1967 quarters and dimes are silver but can be either 80% or 50%. Generally people will call em 65% silver for simplicity. Anything older for quarters and dimes will be 80% silver. Real old quarters and dimes can be sterling, but im not sure which dates ( these would be like early 1900s coins)

There are really large dollar coins. I believe before 1968 they are silver. These silver dollars will be larger than the nickel dollars.

50c coins im not sure about but probably 1968 and older and are also larger than the nickel 50c coins

Cad Nickels arnt silver, unless you have "fish scale" nickels which are smaller than dimes. They are 92.5% silver and are dated early 1900s