Complex sentence: He trained in the offices of Leonard Stokes and Frank T. Verity, practitioners of the Beaux-Arts style, and in 1906 he established his first architectural practice, in partnership with Charles Lovett Gill (the Richardson & Gill partnership was eventually dissolved in 1939).
Split into simpler sentences: He trained in the offices of Leonard Stokes and Frank T. Verity, practitioners of the Beaux-Arts style. In 1906 he established his first architectural practice, in partnership with Charles Lovett Gill (the Richardson & Gill partnership was eventually dissolved in 1939).