Ta, Chi, Tsu, Te, To

A Japanese native would never question this: たちつてと. This is the た行 (Ta gyo) of the Japanese alphabet. But actually, this is so not logical. Just like さしすせそ (Sa, Shi, Su, Se, So). As a child learning Japanese as my second language in America, and also watching my children and husband learn it, I realize we all struggle with this. Why isn't it Ta, Ti, Tu, Te, To or Sa, Si, Su, Se, So?

And then, AI is cheeky enough to offer to answer my question…!

”The reason these kana don’t follow the straightforward pattern is due to historical sound changes. Originally, in ancient Japanese, the sounds were closer to "ti" and "tu." Over time, a phonetic shift added frictional sounds: "ti" became [tɕi] (ち), and "tu" became [tsu] (つ). Similarly, し (shi) replaced an older "si" sound. These changes reflect natural pronunciation evolution where the tongue creates slight friction, shaping the modern sounds we learn today.

Despite these shifts, the kana are still grouped by their original consonant families in the syllabary, which is why the writing system appears irregular but actually preserves the history of the language’s sound development.”