In [[form-functional theory]], hybrid themes are those that combine [[phrase functions]] from the [[sentence]] and the [[period]]. Hybrid types consist of combinations of [[antecedent]], [[continuation]], [[cadential]], and [[consequent]] functions; the initiating function of [[presentation]] is not used, its place taken by the hybrid function compound basic idea. According to William Caplin, there are four main hybrid theme types:^[William E. Caplin, Analyzing Classical Form: An Approach for the Classroom (New York: Oxford University Press, 2013), 100.] 1. antecedent + continuation 2. antecedent + cadential 3. compound basic idea + continuation 4. compound basic idea + consequent