\newcommand\gm{\textit{(m.)} }
\newcommand\gf{\textit{(f.)} }

\newenvironment{translation}[1]{%
    \def\switchtolang{#1}
    % TODO: for now we accept only german, else proper case handling needed:
    \ifdefined\GermanTranslation
        \begin{adjustwidth}{.1\textwidth}{}
        \begin{\switchtolang}
            \itshape
}{%
        \end{\switchtolang}
        \end{adjustwidth}
    \else % do not translate
        % No output
    \fi
}