Complex sentence: With a friend's help he devises a questionnaire to assess the suitability of female partners, But his plans are set off course when he meets Rosie, who doesn't fill many of Tillman's criteria but becomes a big part of his life.
Split into simpler sentences: With a friend's help he devises a questionnaire to assess the suitability of female partners. His plans are set off course when he meets Rosie, who doesn't fill many of Tillman's criteria, but becomes a big part of his life.