Intuitively, the main subject of a right-branching sentence is described first (in the left part) and is followed by additional modifiers (in the right part) (Berg et al., 2011).
the left half of a right-branching sentence is more likely to possess a clearer structure pattern and thus lead to higher generation accuracy than in the right part, since the main subject is usually simpler and clearer than the modifiers that providing additional information about the subjec-t.