To express a strong will more effectively, the frame construction “宁+XP+不+YP” is formed by adding reference items to the construction “宁+VP”. “宁+XP+不+YP” structure has a strong subjectivity. Affected by the natural foot disyllablization, the verb “宁” and “可” are synonymous, and further form a disyllable word “宁可”. To satisfy the requirement of rhythmic symmetry, bisyllables are used in the same frame constructions. Therefore,“宁可+ XP+也不+YP” and other frame constructions appear, and then they gradually develop into a construction family with comparison and selection.