Particle checker
は or が. を or に. で or に. Particles are the part of a sentence a dictionary cannot settle, because the right one depends on what the rest of the sentence is doing. Paste yours and every particle gets checked, with the reason it changed.
What this page checks
- ·は vs が — topic against subject, and the contrastive は
- ·を vs に — object, destination, and the space a motion verb moves through
- ·に vs で — where something exists against where an action happens
- ·と, から, まで, へ, の and the compound particles
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
毎朝、公園に散歩します。
Corrected
毎朝、公園を散歩します。
I take a walk in the park every morning.
1 correction — and why
公園に → 公園を
に marks a destination you arrive at; を marks the space a motion verb moves through. 散歩する is movement across the park rather than arrival at it, the same を as 道を歩く and 橋を渡る. 公園に行く would be correct, because 行く really does take a destination.
More natural
毎朝、公園を散歩しています。
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.
Checking more than one sentence?
A free account keeps every check in one place and shows which grammar points you keep getting wrong — so the same particle mistake stops coming back instead of being re-corrected every week.
The checker itself stays free and unlimited either way. No card, no trial.