Duolingo's Japanese course is a free and accessible way for beginners to learn basic vocabulary and grammar. However, users should supplement their learning with other resources if they want to achieve a higher level of proficiency. The course covers basic Japanese grammar, vocabulary, and sentence structure, but does not cover more advanced grammar structures or complex kanji characters. Users can expect to learn hiragana and katakana as well as some basic kanji characters. While the app is gamified, it has limited speaking exercises and does not provide much explanation or context for vocabulary words. Alternatives to Duolingo include Rosetta Stone, Lingodeer, and textbooks like Genki or Minna no Nihongo.