掲示板 Forums - Why does "達" have the "だち" reading in the word "友達"?

友達 originally only meant the plural form of 友, but over time its usage shifted to refer to both singular and plural.

So, why is 達 pronounced だち instead of たち ? Any time you put two nouns together, if the second noun can accept dakuten on its first kana, it often does.

Cure Dolly discusses the mechanics at ~12:20 in the video linked below. (The specific scenario of joining two nouns is at ~17:55)

Cure Dolly on Kanji sound shifts

I'm by no means an expert. First thing on my mind is rendaku, as that's my constant reminder about how and when voicings change.

It's quite a trip to go around the rules of it, as there are some exceptions and weirdness (Such as 悪口 having two acceptable readings!). But when we're talking of readings changing their voicings, usually it's due to rendaku. Language can also shift over time based on how it's been used.

When you tend to think of kunyomi the way you're taught, it's not wrong while rendaku doesn't apply. Dictionaries tend not to note their rendaku alternatives since inherently voiceless consonants speak for themselves (no pun intended) when rendaku applies to it.

After all, keep in mind that even some words using combinations of kanji might not also follow conventional dictionary kunyomi voicings either, such as 今日. While it's still important to know the kunyomi reading(s), be aware that it's not necessarily consistent.