1 into English using the following set of rules: To correctly translate the sentence, a hierarchical phrase-based system needs to model the subject noun phrase, object noun phrase and copula constructions; these are captured by rules X a , X d and X b respectively, so this set of rules represents a hierarchical phrase-based system that can be used to correctly translate the Chinese sentence.
note that the Chinese word order is correctly preserved in the subject (X a ) as well as copula constructions (X b ), and correctly inverted in the object construc- although it can generate the correct translation in Fig Figure 2: The derivation that leads to the correct translation   The computation of the dominance relationship using this alignment information will be discussed in detail in the next section.