The correct statement of subgrade shaping is subgrade shaping. According to official website's inquiry about subgrade shaping, subgrade is a part of highway engineering, which refers to digging and filling the original topography and landforms by collecting people's mechanical methods, so as to achieve the smooth and flat working order required by road construction. Shaping refers to the adjustment and modification of the shape of a substance to make it meet the pre-set standard requirements. Therefore, subgrade shaping refers to the adjustment and modification of subgrade topography in highway engineering. The process of making it meet the requirements of highway design, but the language "subgrade forming" is unreasonable, because morphological forming is not often used to describe engineering and technical work.