Complex sentence: The Canadian prime minister serves at Her Majesty's pleasure, meaning the post does not have a fixed term; once appointed and sworn in by the governor general, the prime minister remains in office until he or she resigns, is dismissed, or dies.
Split into simpler sentences: The Canadian prime minister serves at Her Majesty's pleasure, meaning the post does not have a fixed term. Once appointed and sworn in by the governor general, the prime minister remains in office until he or she resigns, is dismissed, or dies.