His uneducated comments about classical music showed his lack of refinement.

uneducated 是由前缀 un-（表示"不、非"）和 educated（受过教育的）组成的形容词。un- 否定前缀加上 educated 表示"没有受过教育的"，引申为"粗俗的、缺乏教养的"。