The results (Table 5) show that on aren, there is no degradation if we limit the maximum order of the n-grams to 3.
on zhen/enzh, there is improvement by BLEU(%) Max n-gram order aren zhen enzh 1 38.7 26.8 40.0 2 44.1 27.4 42.2 3 44.9 28.0 42.4 4 44.9 28.5 42.6 considering 4-grams.