Tomodachi vs. Tomo vs. Dachi: Friend in Japanese
Tomodachi (友達/ともだち) is one of the Japanese words that many people know, meaning friend(s).
Although the Kanji character 達 pronounced as Tachi is often used to make a plural expression, the word Tomodachi can also be singular.
Tomodachi vs. Tomo vs. Dachi
Tomodachi is an interesting noun because both the Tomo (友/とも) part and the latter word Dachi (達/だち) can mean friend(s) on its own.
However, the nuances differ between the three.
Tomo (友/とも)
Tomo sounds more formal than Tomodachi and is similar in usage to Houyu (朋友/ほうゆう), which is an archaic word for Tomodachi, meaning friend(s).
Tomo and Houyu are like written language, used like 我が友 (pronunciation) or 我が朋友 (pronunciation),
which are rigid expressions for 私の友達 (pronunciation) meaning my friend(s), often seen in old lyrics.
Dachi (達/ダチ)
Dachi sounds much more casual than Tomodachi.
It is a kind of slang word often used by young males, like 俺のダチ (pronunciation), which is a very informal way to say 私の友達.
Tomodachi (友達/ともだち)
The combination of Tomo and Dachi, Tomodachi sounds neutral compared to the first two.
Tomodachi is close in usage to Yujin (友人/ゆうじん) (pronunciation), which also means friend(s) in the Japanese language.
Both Tomodachi and Yujin are colloquial expressions frequently heard in everyday conversation.
(Reference Pages: Goo Japanese Dictionary 友達, 友 )
