Is there a generally accepted "rule" for truncating loan words?


I've noticed that sometimes loan words (usually pairs) are truncated to just
the first two morae from each word:

>   * Smash Brothers ➤ スマッシュブラザーズ ➤ スマブラ
>   * "Don't mind." ➤ ドンマイ
>

I assume this is done to shorten the writing and pronunciation. Is the
accepted practice to just grab the first two morae from each word and shove
them all together?




It depends on the words and how they are pronounced, although the pattern you
noticed is common.

For example, the following don't fit the pattern you see:

> Brad Pitt -> ブラピ
>
> Ice Cream -> アイス
>
> Convenience Store -> コンビニ

There has been a lot of linguistic studies about this and many patterns that
exist. One rule is that they are always truncated to 2 to 4 mora. Also,
[濁音]{だくおん} are avoided if possible and generally heavy syllables are avoided
at the end.

[Here is a link to one
paper](http://roa.rutgers.edu/files/532-0802/532-0802-LABRUNE-0-0.PDF) if you
are interested.




It depends on the words and how they are pronounced, although the pattern you
noticed is common.

For example, the following don't fit the pattern you see:

> Brad Pitt -> ブラピ
>
> Ice Cream -> アイス
>
> Convenience Store -> コンビニ

There has been a lot of linguistic studies about this and many patterns that
exist. One rule is that they are always truncated to 2 to 4 mora. Also,
[濁音]{だくおん} are avoided if possible and generally heavy syllables are avoided
at the end.

[Here is a link to one
paper](http://roa.rutgers.edu/files/532-0802/532-0802-LABRUNE-0-0.PDF) if you
are interested.

