\documentclass[german]{article}
\usepackage[french,english]{babel}
\begin{document}
\raggedright
The expansion of fixed document element names
depends on the language, e.g., in English
we have ``\refname'' or ``\chaptername''.

\selectlanguage{german} Auf Deutsch ergibt sich
``\refname'' oder ``\chaptername''.

\begin{otherlanguage}{french}  Voice en
fran\c cais: ``\refname'' ou ``\chaptername''.

\foreignlanguage{english}{But in short
phrases  ``\refname'' does not change!}
\end{otherlanguage}
\end{document}