Language HIIT — A CEFR-Aware Vocabulary Workout 

ENRURO treats vocabulary like a workout rather than a linear course. 

Its built-in CEFR-aware scheduler can mix vocabulary from A1 to C2 within the same training flow, while your own Learn and Know decisions continuously shape the cards that remain in your workout.

You shape the difficulty 

Every card is also a small decision.

If a word is obvious to you, choose Know and it leaves the normal training rotation. If you still need to work on it, choose Learn and keep it in your active training pool.

Over time, easy vocabulary naturally falls away. The remaining deck becomes more challenging for you, because it increasingly contains the words you have not yet marked as known.

The scheduler provides the structure. You decide what you actually know.

Your session, your pace   

Set a daily goal of 10, 20, 30, or 40 cards. ENRURO builds the session from the vocabulary still available in your training pool.

There are no push notifications telling you when to study. Your pace is your own.

Why “HIIT”?   

The name is inspired by high-intensity interval training: instead of repeating one comfortable load forever, the workout varies the challenge.

ENRURO applies that idea to vocabulary practice. Familiar words, working vocabulary and genuinely difficult cards can appear within the same training flow.

The loop stays simple   

Try to remember the card first. Reveal it. Read the example when you need context. Then make one honest decision: Learn or Know.

Use Undo if you made a mistake.

No complicated Again / Hard / Good / Easy scale. No AI deciding what you know. The training pool gradually focuses itself through your own decisions.

An illustrative example   

Imagine that a session shows you:

water → obvious → Know
however → familiar but uncertain → Learn
to take something for granted → difficult → Learn

Next sessions no longer need to spend ordinary training time on water. Your workout gradually concentrates on the vocabulary that still challenges you.