（たぶん、正しい言葉は「意味合い」でしょうか？イタリア語で、「sfumatura di significato」です。。。）
May 23, 2013 12:58 PM
Answers · 2
They are almost identical in meaning but 友達 is an extremely common word that can sometimes sound a little casual while 友人 is rather formal and used only in formal conversations and writing. So they are actually very different in register.
May 24, 2013
In the meaning of kanji, "達" is plural and "人" is single, but there is no different between "友達" and "友人" after all.
You can say both with the same meaning.