oneThis plural form is used for numbers like: 1
%{count} file
otherThis plural form is used for numbers like: everything else
%{count} files
%{count} file
%{count} files
%{count} fil
%{count} filer
%{count} file
%{count} files
%{count} file
%{count} files
%{count} fil
%{count} filer