Complex sentence: The Provisional Government is considered to be the de jure government of the Korean people between 1919 and 1948, and its legitimacy is enshrined in the preamble to the constitution of the Republic of Korea.
Split into simpler sentences: The Provisional Government is considered to be the "de jure" government of the Korean people between 1919 and 1948. Its legitimacy is enshrined in the preamble to the constitution of the Republic of Korea.