Duolingo: Language Lessons offers a free version that provides access to a wide range of language courses, while additional features are available through a paid subscription.

While an internet connection is needed for initial downloads and some features, Duolingo: Language Lessons also offers offline access to certain lessons once they are downloaded.

You can contact Duolingo support or send feedback through the app’s help section or by visiting their official website, where you can submit inquiries or access their help center.

You can manage or cancel your Duolingo: Language Lessons subscription through the app settings or your account settings on the Duolingo website, depending on how you initially subscribed.