how happy we are to see each other again为何不可说how happily

Question

如题所述

Answer 1

正常语序：

we are how happy to see each other again
happy是表语，所以用happy不用happily

Answer 2

这句话要这样理解：How happy we are（to see each other again）！
happy是are的表语，不是副词状语。