Bests & Worsts Reviews from Amazon

My teen son has been homeschooled since eighth grade. One of his main interests in languages. In his first couple years of homeschool, he attempted to learn Japanese using Rosetta Stone (he went through the full first level and most of the second), by using the first Genki book and workbook, various other beginner books (as I scroll through the popular books on Japanese language in Amazon, I see we now own many of the titles...), and by doing a few other things like us just going through flashcards of hiragana and katakana. Partway through last school year (Jan 2017), he told me he feels like he's learned a lot of Japanese, but said he felt he wouldn't be able to put together even the simplest sentence - written or spoken - if he was put to the test. As with all things homeschool, there's some trial and error, and we occasionally try something that doesn't work. This was definitely one of those things. I knew he was frustrated, but not at all ready to give up. We came across Japanese From Zero! Book 1. When he started using that first workbook and discovered the hundreds of free videos the author, George Trombley, put on YouTube, I mean, this kid was transformed. He ate that book up, and book 2. By the end of that school year (June 2017) he'd gone from saying he couldn't say "How are you?" to being comfortable enough to converse with teens in Japan. In the summer he completed book 3. This school year (starting September 2017) he began Japanese From Zero! 4 and Kanji From Zero! 1, and he's working his way through both now. He keeps up with the supplemental videos from George. When George asks a question, I'm continually impressed at how my son replies correctly, without fail, before George supplies the answer. My son just asked me what I was doing, and I told him I was typing up a review for these books -- he said I should say he doesn't feel he started actually learning Japanese before he opened the first from Zero! book. These books and the free supplemental videos are by far the best system we've found for any English speaker who wants to learn Japanese. UPDATE MAY 2019: My son graduated homeschool Spring 2018. He asked if he could take a placement test for Japanese at the university he was planning to attend. Recall he’d only gone through George Trombley’s Japanese From Zero! books 1-4 plus Kanji from Zero! book 1 and the free YouTube videos. From the placement test, he was put in 3rd semester Japanese. He likely tested into 4th semester, but as 4th is only offered each Spring, he was happy to go into 3rd semester. And how did he do? He got a 4.0 in Japanese both semesters. Each class was worth 5 credits, and he was given an additional 4 credits for each class he skipped because of the placement test, so he ended up getting 18 credits as a freshman, just from taking those two classes. The Japanese from Zero system definitely works.