Wrong quotation marks in \foreignquote

Question

This is quite embarrassing but I cannot get \foreignquote to work although it seems so straigth forward ...

I have a German document containing English quotes.

\documentclass[a4paper,ngerman]{article}

\usepackage{babel}
\usepackage[T1]{fontenc}
\usepackage{lmodern}

\usepackage{csquotes}
\usepackage{parskip}

\begin{document}
    Dies ist ein deutschsprachiges Dokument.
    \enquote{Deutsche Zitate funktionieren wie erwartet.}

    \foreignquote{english}{But foreign quotes use \enquote{German} quotation marks, as well.}
\end{document}

German works fine, but the English quotes use German quotation marks even though I am using \foreignquote{english}. According to the documentation page 7 already the outer quotes should be English quotes. Although I don't care much about that the inner quotes have to be English quotes. As long as it is just English it's easy enough to just type the quotation marks as `...' but why does \foreignquote not work?

I have considered whether I may need to load English as a secondary language explictly with \usepackage[english,main=ngerman]{babel} but that does not make a difference and it would have suprised me if it did because there was no warning about a missing language and the log actually said "Package babel Info: Importing basic data for english" even without loading English explicitly.

Answer 1

As far as I understand you need to load csquotes with the option autostyle in order to make it babel/polyglossia aware:

\documentclass[a4paper,ngerman]{article}

\usepackage{babel}
\usepackage{lmodern}
\usepackage[T1]{fontenc}

\usepackage[autostyle]{csquotes}
\usepackage{parskip}

\begin{document}
Dies ist ein deutschsprachiges Dokument.
\enquote{Deutsche Zitate funktionieren wie erwartet.}

\foreignquote{english}{But foreign quotes use \enquote{German} quotation marks, as well.} --- corrected
\end{document}