漢語的 X A (Y) D 比較句式帶有「-過2」這個不具語音形式的比較詞素，這個後綴式的詞素虛化自X A-過 Y (D)比較句式中的動詞後綴「-過1」。詞素「-過2」的虛化本質是造成X A (Y) D 比較句式中差值度量詞組（D）必需出現和此一句式中形容詞不得受程度副詞修飾的原因。而且X A (Y) D 這種比較句式的特有語法和語意特性多半源自「-過2」這個比較詞素的虛化本質。

The X A (Y) D comparative contains a covert weak comparative morpheme (i.e. the covert verbal suffix -guo2) that is grammaticalized from the verbal suffix -guo1, meaning ‘exceed’ or ‘surpass’, in the X A-guo1 Y (D) comparative. The “weak” nature of -guo2 is the “virus” that makes the X A (Y) D comparative differ from the X bi Y A D comparative not only in obligatoriness of the measure phrase but also in further modification by degree adverbs. And most of the properties specific to the X A (Y) D comparative in fact originate from the weak nature of the covert verbal suffix -guo2.