Non-defining relative clauses with: who,which,where

Non-defining relative clauses, which give extra information and
which can be left out, have a comma before the relative clause
and a comma or full stop after it.

Ex: Jim, who loves cooking, made that cake.
      Penzance, where my friend Sally lives, is a busy seaside town.
      Strawberries,which are my favourite fruit, are delicious with sugar
      and fresh cream.