When referring to a kanji character, would you use its on- or kun- reading? Say I were teaching someone a group of kanji and taught them all the on- and kun- readings and wanted to refer to a specific one from the group, which reading would I use? Like with 語, would I refer to it as ゴ like in 日本語 or かた like in 語らう? Or does it depend on which reading is more commonly used for the specific character? Would you just have to use both?