呀
yayā HSK4

particle used to express surprise or mild emphasis

Phonosemantic compound. 口 represents the meaning and 牙 represents the sound.

Components

口
口 Meaning component
kǒu, kou mouth
牙
牙 Sound component
yá tooth

Character Evolution

Seal form
Seal Shuowen ~100 AD
Regular Modern

Historical Pronunciations

Middle ChineseOld Chinese
Zhengzhangŋraː
hŋraː
Unicodenga
xa

說文解字

《說文新附》：“呀，張口皃。从口，牙聲。”

Sources

Character origin
漢語多功能字庫
Readings & variants
Unicode
Historical pronunciations
Zhengzhang Shangfang
Historical images
Academia Sinica
Etymology
Shuowen Jiezi (說文解字)