By default, if you are using Asset Bank's multi-language functionality, English is the default language. This means that when users enter values for text attributes when adding or editing an asset they will always see English first, followed by a 'translation' field for all of the languages they want to be able to edit (as specified in the 'Languages visible when editing assets' checkboxes in their profile).
The way Asset Bank works is as follows: if a user is viewing the site in a language that is not the default, for example 'French', the user will see French translations (for page copy, labels, asset attribute values, etc) if these translations have been entered. If not then the user will see items in the default language.
If you want your Asset Bank to be less English-centric then you might want to change the default language so that it does not actually represent a real language but instead holds the default translations for all the other (real) languages. Here's how to do that:
Go to Content->Languages and edit the default language.
Change its name to 'Default', its native name to 'Default', its code to e.g. 'df' and check the checkbox 'Not a real language'.
Add English as a new language, with name 'English' and code 'en'.
The following will now happen:
Users will not be able to select the default language from the selector at the top of the page, or in their profile, as it is not a real language. (Admin users will still be able to select it in the top selector as they will presumably still want to edit the default language content in the pages).
When a user edits an asset the idea is that they can enter whichever language they like into the first (default) field for text attributes - typically they would enter text in their native language.
They can then enter translations for whichever of the other languages they want - but they can skip the field shown for their native language as this can just inherit the text from the default.