Simplify the following text for a Grade 5 native English-speaking person.
Original: Boris Karloff ( 23 November 1887 â `` 2 February 1969 ) , whose real name was William Henry Pratt , was an English-born actor who emigrated to Canada in 1909 .
Simplified: Boris Karloff a.k.a. William Henry Pratt ( November 23 , 1887 â `` February 2 , 1969 ) , was an English actor .