% arara: pdflatex
\documentclass[british,francais,american,canadian,canadien,dutch,a4paper]{article}

\usepackage{tracklang}

\begin{document}

Languages:
\ForEachTrackedLanguage{\ThisLanguage}{\ThisLanguage\space
(ISO \TwoLetterIsoLanguageCode: ``\TrackedIsoCodeFromLanguage{\TwoLetterIsoLanguageCode}{\ThisLanguage}''). }

Dialects: \ForEachTrackedDialect{\ThisDialect}{\ThisDialect\space 
(\IfTrackedLanguageHasIsoCode{\TwoLetterIsoCountryCode}{\ThisDialect}%
 {ISO \TwoLetterIsoCountryCode: 
  ``\TrackedIsoCodeFromLanguage{\TwoLetterIsoCountryCode}{\ThisDialect}''}%
 {no specific region};
root: \TrackedLanguageFromDialect{\ThisDialect}). }

``english'' \IfTrackedDialect{english}{has}{hasn't} been specified.

``british'' \IfTrackedDialect{british}{has}{hasn't} been specified.

``flemish'' \IfTrackedDialect{flemish}{has}{hasn't} been specified.

``dutch'' \IfTrackedDialect{dutch}{has}{hasn't} been specified.

``english'' or an English variant 
\IfTrackedLanguage{english}{has}{hasn't} been specified.

Language for ISO \TwoLetterIsoCountryCode\ ``GB'': 
\TrackedLanguageFromIsoCode{\TwoLetterIsoCountryCode}{GB}.

Language for ISO \TwoLetterIsoCountryCode\ ``CA'': 
\TrackedLanguageFromIsoCode{\TwoLetterIsoCountryCode}{CA}.

Country ISO \TwoLetterIsoCountryCode\ code for ``canadian'':
\TrackedIsoCodeFromLanguage{\TwoLetterIsoCountryCode}{canadian}.

Dialects for language ``english'':
\TrackedDialectsFromLanguage{english}.

\end{document}