From a letter to a sentence.

You were taught that a letter has a sound. It has several, and which one you get depends on the company it keeps.

• Letter TrapPlay →The letter a is six different sounds. Hear the word and say which one it made.

Every one of these plays real speech at real speed and asks you what happened. Nothing to set up, nothing that can fail.

• Street FormPlay →Hear it at full speed and write down what was said. You know every word and you will still miss it.
• Can / Can'tPlay →Which one did you hear? It was never the t — you have been listening for the wrong thing.
• Off the BeatPlay →Tap the words that stayed loud. The ones you miss are the same kind every time.
• The TunePlay →Same words, different melody, different meaning. And no, not every question goes up.

The machine is not scoring your accent. It is telling you what a listener heard — which is a lower bar than good pronunciation, and a far more useful one.

• MirrorPlay →Say the line. The machine writes down what it heard, not what you meant.
• ClustersPlay →Four consonants in a row with no vowel to rest on. strengths, texts, twelfth.
• No GapPlay →Say it as one piece. Any silence in the middle and it shows you exactly where.
• The SlidePlay →Two vowels meeting. English grows a small w or y to bridge them, whether you meant it or not.
• Real SpeedPlay →Now say it in the time a native takes. Careful and slow is its own kind of wrong.

A bad vowel you can hear. A wrong preposition you cannot — you will reread your own sentence ten times and see nothing. So these ask you to find it, and offer you nothing.

• The InvisiblePlay →a, the, in, on, at. No meaning at all, and a grader sees them from across the room.
• Goes WithPlay →You make a decision. You do not do one. Nothing here breaks a rule and every line is wrong.
• The JoinPlay →Two ideas, one sentence, one joining word. Most languages use two and the habit survives.