The tutor lets a mistake pass. The lesson does not

A tutor that corrects every slip turns a conversation into a test. The learner starts weighing each word, and the talking stops. So the tutor on the Studify platform lets most mistakes pass. The lesson does not. A detector the learner never hears writes them down, and the ones that repeat are built into the exercises, later in the same lesson and in the lessons that follow. Here is how it works in Studify, our English tutor.

What the tutor corrects aloud

Only what gets in the way of the meaning: when the tutor would have to guess what the learner meant, or the learner said the opposite of what they plainly intended. It corrects by recasting. The right form goes into its reply, with no "you said", and the conversation goes on.

At most one correction per reply, and most replies have none. Articles, prepositions and a missing third-person s never get a comment, and the speaking task never stops for a small mistake.

A second listener

Every turn the learner finishes also goes to a detector, a second model that reads it in the background while the tutor is already answering. The conversation never waits for it.

Each slip it finds is written down under a rule from a fixed list, with the learner's words and the correction, and it counts only if those words are really in what the learner said. The list is fixed so that the same mistake always goes under the same name: a mistake that keeps changing its name cannot be counted.

Twice before it counts

One slip proves nothing, and working on it would turn a slip of the tongue into a drill. So a single one is never worked on. A rule that comes up twice, in one lesson or across several, is. At most three rules are worked on at a time, the most frequent first.

Woven into the exercises

A Studify lesson runs twenty minutes in six parts, and its exercises are built for each learner while it runs. Three parts take the lesson's own slips: practice, fix-ups and the wrap-up. Recall, which opens the lesson, takes only those carried from past lessons.

In practice, a slip does not get an exercise of its own. It changes the items of the lesson's form instead: if the third-person s keeps slipping, the items get third-person subjects, and the learner has to say the form again and again. Each rule comes with the learner's own sentence, so the items are built on the structure they got wrong, not on the rule's name. A rule that cannot be built in naturally is left out: a strange sentence is worse than a missed rule.

Fix-ups and the wrap-up are built later, each as its part begins: a short spoken exercise on the repeated slips, then homework on the same ones.

The practice items are built a part ahead, while the new form is on, so that they are on the board the moment practice starts. So practice takes only the slips of the lesson's first minutes and those carried from past lessons; whatever comes up later goes to the fix-ups.

The lessons that follow

The same rules are carried into the next lesson. They come back first, in recall, together with the last homework, and then in the practice items, the fix-ups and the new homework.

A carried rule is settled when a lesson reaches its end and the slip does not come back. A lesson the learner left halfway proves nothing. If the slip returns later, it has to come up twice again before it is carried.

What the learner sees

On their screen, nothing until the end: no red marks and no tally. Then a closing card on the board names what will come back. The report after the lesson lists "What we fixed", each slip as the struck-out words and the fixed ones, and "Work on recurring slips": what has settled and what is coming back, under plain names, never codes.

In the lesson, the learner just talks. Their mistakes come back to them as exercises.