To overcome these limitations, many syntaxbased SMT models have been proposed (Wu, 1997; Chiang, 2007; Ding et al., 2005; Eisner, 2003; Quirk et al., 2005; Liu et al., 2007; Zhang et al., 2007; <cite>Zhang et al., 2008a</cite>; Zhang et al., 2008b; Gildea, 2003; Galley et al., 2004; Bod, 2007) .