What is the most commonly used way to apologize in Japanese?


Also, would you say something different whether that person is someone you
know or not?




The most common ways are Sumimasen and Gomennasai. The first one is more
formal while the second one can be used with people who are closer in terms of
relationship




There is no most commonly used way, it depends on the situation.

**Informal**

>   * わりい (←sounds like you aren't really showing remorse, male)
>   * 悪い (male-ish)
>   * すまん (male-ish)
>   * ごめん
>

(If you say any of these twice in a row, like ごめんごめん, that also makes it
sounds like you aren't showing remorse.)

**Regular**

>   * 申し訳ない (feels proper but not particularly polite due to ending with a
> plain ない)
>   * ごめんなさい (feels slightly childish)
>   * すいません（でした） (probably the most common in everyday non-business speech)
>   * すみません（でした）
>

**Business**

>   * 申し訳ありません（でした）
>   * 申し訳ございません（でした）
>   * 申し訳なく存じます
>   * お詫び申し上げます
>

Often prefaced by 「大変ご迷惑をおかけして」 or similar, depending on how bad of a thing it
was.

Especially in business, there are plenty more variations, but I'd say these
are the more commons ones.

