Best language learning course

[AutumnSuns]

Looking to learn a language with DH together. Either mandarin, french, German or Spanish. What’s the best course to do together at home? Not to worried about cost/looking for the cheapest at the moment as would have paid to go to classes and would rather pay for something that is better quality.
Any suggestions on language to learn would be good too.

Duolingo is free and gives you a chance to try out a few languages and see which you prefer. If you find one you like you can always look for paid for courses in the same language. I've been learning Scottish Gaelic on duolingo

I'd highly recommend Michel Thomas (all of those languages are available). It shortens the initial learning curve and builds your confidence quickly. It's focused on building sentences and grammar more than vocab but you really feel like you pick it all up easily.

Not a course but I'd recommend Anki for vocabulary. It's a flashcard program and app that uses spaced repetition, it's very clever.