Review algorithm

How words are selected

A session is assembled from scratch every time, and its composition depends on one thing: how many reviews have piled up relative to the size of your dictionary. The more words are waiting, the longer the session and the fewer new words it holds — down to none at all. Once the backlog clears, new words come back on their own.

Reviews come before new material

The rule is simple: first whatever is about to be forgotten, then everything else. A new word added on top of a large number of overdue reviews will almost certainly be forgotten along with them — so Tomyo reduces the accumulated queue first.

Hence an effect that looks like a malfunction from the outside: you keep studying and no new words appear. What is actually happening is that Tomyo sees a large backlog and hands the whole session over to it. That is a priority, not a stop.

The session adapts to the load

With a noticeable backlog the session grows longer, so it clears faster, and side tracks such as new grammar and new radicals switch off for a while. That keeps your attention focused while there is still material to catch up on.

As the backlog shrinks, everything returns: sessions get shorter again, new words reappear, grammar and radicals switch back on. None of this needs any action from you.

Stability of the composition

If the composition were recalculated strictly by formula, a single overdue answer would change it: new words today, none tomorrow, new words again the day after. So near the switching points Tomyo keeps the previous mode and changes it only once the load has shifted appreciably.

What else shapes the session

The daily session limit — once it is used up, no new words are added that day.
New-word pace — if you have deliberately limited the intake, the freed slots go to reviews.
Your HSK level — words beyond it never enter a session.
Your plan — grammar and radicals are part of the session on Plus.

What to do if…

I study every day but get no new words

Almost always this is the review backlog: while it is large, the session belongs to it. Clear the backlog and new words return by themselves. If you switched on a new-word pace, check it in settings — it limits new material on purpose.

The session got longer than usual

That is by design: with many reviews waiting, the session grows so the backlog clears sooner. It returns to its usual size once the reviews are done.

Grammar and radicals disappeared

Side tracks switch off while a large vocabulary backlog is pending and come back once it is cleared. If they never appeared at all, check your plan — they are part of the session on Plus.