I will explain a problem of plurals in brief. In English there is only one plural form:
files (any number of files more than 1)
This is very simple approach. Many other languages I know have more difficult approach.
failas (for 21, 31, 41, 51, ..., 101, 1001,... files)
failai (for 2 to 9, for 22-29, 32-39,... files)
failų (for 10, 20, 30, 40,.. 100,... files and for 11 to 19 files)
All above words are different three plural forms of Lithuanian language. Similar approach to plurals is in russian, polish languages. Some languages has even four plural forms.
Plurals in amule are still not supported. It means that plural words cannot be translated correctly into many languages. It would be greate to have plurals support in amule!