Complex sentence: Indentured laborers and the slaves, who could not take part in Carnival, formed their own, parallel celebration called Canboulay, a precursor to Trinidad and Tobago Carnival.
Split into simpler sentences: Indentured laborers and the slaves, who could not take part in Carnival, formed their own, parallel celebration called Canboulay. Canboulay is a precursor to Trinidad and Tobago Carnival.