Complex sentence: The first Czech school, the Catholic one, was formed in 1920, it was however replaced by completely new large Czech school built in 1931 and named after Tomáš Garrigue Masaryk, President of Czechoslovakia.
Split into simpler sentences: The first Czech school, the Catholic one, was formed in 1920. It was however replaced by a completely new large Czech school built in 1931 and named after Tomáš Garrigue Masaryk, President of Czechoslovakia.