The remainder of the chapter introduces three predominant instantiations of syntax-based models: hierarchical phrase-based SMT (Hiero) <cite>(Chiang 2007)</cite> , which is a non-labeled syntax-based SMT approach arising from the phrase-based approach; syntax-augmented machine translation (SAMT), which introduces the notion of soft labels while keeping the nonlinguistic phrase notion; and GHKM (Galley et al. 2004 ), which only extracts translation rules consistent with constituency parse subtrees.