Many people ask me about this topic, and if you follow the link you’ll find a great, great list for people in all stages of Japanese language learning! But for beginners, I personally recommend these three:
jGram is a database of Japanese grammar (that’s why jGram stands for “Japanese Grammar”) put together by the jGram community. So basically, normally people like you and me! Think of it like a wiki for Japanese grammar. This website is great for people studying for the JLPT, as they separate grammar by JLPT level for you, so you can study according to your level. I used this website a lot when studying for the JLPT, and it was really useful. Another thing they do is have a check system, that allows users to make sure things are reliable or not. Things that don’t have a high reliability rating are things you might want to look out for (or check yourself!). They also have a “useful phrases” section that is, surprisingly, really useful.
iKnow revolutionizes how you learn vocabulary. Right now, you can use it to learn Japanese or English vocabulary, but I’m guessing the first one will be more useful to you. They have different ways for learning vocabulary, with the first being flashcards. What I like about their flashcards is that after they ask if you know a word or not, they don’t trust you (who would trust you?) and then ask you to pick it out of 5-10 multiple choice answers, further solidifying your knowledge (or discovering the lack thereof). My other favorite section is the “dictation section.” In this section, a voice actor reads out a sentence, and you have to fill in the blanks. Eventually, it gets to the point where you have to fill in the entire sentence after someone reads it to you. There are other features as well, you’ll just have to visit it to find out about it yourself!
#2: Tae Kim’s Guide to Japanese
This is as close as you’ll get to finding a free online Japanese textbook, and a good one at that. Tae Kim has done an amazing job putting together a great list of Japanese guidance. It is very thorough, reliable, and you’ll always learn something new. There are plenty of examples, plenty of “extras,” and because of these things, I always come to Tae Kim’s Guide to Japanese first, even before searching for something on Google. I know that I’m always going to find what I’m looking for (and more). Plus, fans of Tae Kim helped to translate this guide into approximately 10 different languages, which makes it even more useful for more people around the world! This is Japanese Language philanthropy at its best. Go check it out!