Complex sentence: This policy was rejected and the PSI split in 1921, with the formation of the Italian Communist Party, and in 1922, when Turati's group was expelled and established a new party, the Partito Socialista Unitario (PSU).
Split into simpler sentences: This policy was rejected and the PSI split in 1921, with the formation of the Italian Communist Party. In 1922, when Turati's group was expelled and established a new party, the Unitary Socialist Party (PSU).