Japanese Grammar Checker
Paste a Japanese sentence and get it corrected — with the grammar rule behind every fix explained in English. Free, no account, no limit on how wrong you are.
What you get back
Here is a real example. Every correction names the grammar point, because knowing which character changed teaches you nothing about the next sentence.
You wrote
昨日友達に映画を見に行きました。
Corrected
昨日友達と映画を見に行きました。
Yesterday I went to see a movie with a friend.
1 correction — and why
友達に → 友達と
と marks the person you do something together with; に marks a target or destination. 行く already takes に for the place you are going, so the companion has to be marked with と — 友達に行く would read as "go to a friend".
More natural
昨日、友達と映画を観に行きました。
Why this exists
Lang-8 shut down. HiNative answers arrive hours later, if at all. italki costs money per correction. Meanwhile the question “is this sentence right?” is the single most common thing a Japanese learner needs answered, and it needs answering in seconds, not tomorrow.
This checker corrects particles, conjugation, word order, politeness register, and word choice, then explains each fix in plain English and estimates the JLPT level of what you wrote. Every check produces a permanent page you can link, bookmark, or send to whoever asked.
What it will not do
It checks Japanese sentences and nothing else — it is not a translator, a chatbot, or a homework machine. Input has to be in hiragana, katakana, or kanji, and one sentence at a time.