I've tried to learn Spanish four separate times in my adult life, and Duolingo is the only method that's actually stuck for more than six weeks. That's not because it's revolutionary in concept—language learning apps have existed for years—but because it's figured out how to weaponize AI in ways that make daily practice feel less like homework and more like a game you're slightly addicted to playing.
Duolingo is the best option for time-strapped professionals who want to build genuine conversational skills through consistent, brief daily practice. Skip it if you need industry-specific vocabulary or have a hard deadline for business fluency, but for everyone else looking to add a language to their toolkit over 6-12 months, this is your best bet at this price point.