Causative and causative-passive checker
させる and させられる are two forms and three argument-marking rules, and the mistake is almost never the verb ending — it is which particle the person takes. Paste a sentence and see whether the maker, the doer and the object are all marked right.
What this page checks
- ·Causative endings: ～せる／～させる, and the contracted ～す forms
- ·Whether the causee takes に or を — the part that goes wrong most
- ·Causative-passive ～させられる and its contracted ～される
- ·Permission vs. coercion: させてあげる, させてください, ～させてもらう
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
先生は学生を漢字を書かせました。
Corrected
先生は学生に漢字を書かせました。
The teacher made the students write kanji.
1 correction — and why
学生を → 学生に
With a transitive verb, を is already spoken for by the object (漢字を), so the person made to act takes に. を for the causee is only available when the verb is intransitive — 学生を立たせる is fine, 学生を漢字を書かせる is not, because a clause cannot carry two を.
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.