Complex sentence: Up until 1977 West Rouge was not actually part of Toronto or Scarborough it was part of the township of Pickering, but in 1977 it was transferred over to the Borough of Scarborough.
Split into simpler sentences: Up until 1977 West Rouge was not actually part of Toronto or Scarborough. It was part of the township of Pickering, but in 1977 it was transferred over to the Borough of Scarborough.