https://app.memrise.com/dashboard

Memrise is an interactive language learning program that’s fun and free to use. It allows you to really dig in to your language learning with short, repetitive lessons that drive home the skills you’re learning.

https://apps.ankiweb.net

Do you need help memorizing vocabulary, grammar drills, and more? This open source program lets you create personalized flash cards to make your language study a little easier. As Anki describes their program, it “makes remembering things easy. Because it is a lot more efficient than traditional study methods, you can either greatly decrease your time spent studying, or greatly increase the amount you learn. … Anyone who needs to remember things in their daily life can benefit from Anki. Since it is content-agnostic and supports images, audio, videos and scientific markup (via LaTeX), the possibilities are endless.”

https://www.thoughtco.com/languages-4133094

“Thousands of resources for both students and teachers of second languages, from basic vocabulary and grammar guides to advanced writing and conversation exercises.”

https://www.languagezen.com/en

Currently only offering Spanish, Language Zen has a free version of language learning that includes personalized lessons that adapt to your interests, such as practice from music and tv the program selects just for you. You can continue to study for free or choose a paid version. Other language offerings seem to be on the way.

https://www.bbc.co.uk/languages/index.shtml

This archived site from the BBC includes guides to languages of the world, lessons and exercises for 40 languages, video tutorials and interactive courses, and more.

https://lingualift.com/blog

The LinguaLift blog provides weekly study tips, resources, weekly challenges, helpful articles, and inspiration to learn languages. The rest of the website is a full resource for language learning, including paid lessons and other paid and/or free resources.

https://www.importanceoflanguages.com

This website is an excellent resource for language learners. Focused on 10 languages, it provides specific information on why these languages are important to learn. Beginners guides for each featured language include such items as:

• History of the language
• Why learn the language
• The alphabet and numbers
• Vocabulary, common words, and words used in English
• Maps of dialects and countries
• Grammar rules

Each language page includes links to free online study/courses, websites, videos, audio files, language learning tips and tools, and more. The site also has a listing of languages by country.