The word 鞋子 is formed by combining the character 鞋, which itself is a pictophonetic character composed of the "leather" (革) radical suggesting the material and the phonetic component 圭 (historically 鞵), with the common noun suffix 子. This suffix 子, when attached to certain nouns like this, doesn't add specific meaning but often gives the word a more concrete, everyday object feel in modern Mandarin, resulting in a complete term for "shoe".