Complex sentence: After J. M. Barrie the most successful Scottish playwrights of the early twentieth century were John Brandane and James Bridie, the pseudonyms, respectively, of doctors John Macintyre (1869-1947) and Osborne Mavor (1888--1951).
Split into simpler sentences: After J. M. Barrie the most successful Scottish playwrights of the early twentieth century were John Brandane and James Bridie. The pseudonyms, respectively, of doctors John Macintyre (1869-1947) and Osborne Mavor (1888--1951).