什

Person radical on the left. The historical sense of 什 was "a group of ten people" - a military squad or household unit - so the radical fits the original people-counting meaning. The interrogative shén reading developed later in spoken Tang/Song Chinese and lost that connection. Same radical heads 你, 他, 们.

Right side 十 supplies both sound and the original meaning. For the shí reading the match is direct: a 什 was historically a unit of ten people or ten families. The interrogative shén reading is a colloquial drift from shí - the vowel nasalised and the tone shifted in Tang-era spoken use, leaving a phonetic that no longer cleanly matches the modern reading.