Show the relationship, don't translate it: animated preposition diagrams
The first cut of the preposition page was text cards full of Korean — wrong for an English-learning tool. Reworked it to animated SVG diagrams + English only: a ball moving into / over / through a box, so you feel the relationship instead of reading a gloss.
The feedback was blunt and correct: the preposition page was too crude, and too Korean. For a tool whose whole point is learning English, a card that explains "into" with a paragraph of Korean is teaching you to translate, not to understand. Prepositions especially — they're spatial relationships, and the honest way to teach a spatial relationship is to show it.
So the page got reworked around one idea: show the relationship, don't translate it.
Each core preposition is now an animated SVG. A reference box, a moving ball, sometimes an arrow or a target:
into— the ball travels from outside the box to inside it.over— the ball arcs above the box without touching.through— the ball enters one side and exits the other.off— the ball lifts away from the box's surface.about— the ball orbits the box.from— the ball leaves a marked source;to— it arrives at a target.
It's SMIL (<animateMotion> along a path), so it's self-contained, loops gently, and needs no JS. The motion does the explaining.
And the words are now English only: each card is the diagram + the preposition + a one-line English sense ("entering — often becoming") + two English examples ("walk into the room", "refactor it into modules"). The Korean glosses are gone from the primer. The only Korean left on the page is in your own mined notes under "from my clips" — that's your data, and it's secondary to the picture.
The lesson isn't really about prepositions. It's that an immersion tool's teaching surface should be in the target language, and an abstract relationship should be drawn before it's described. The first version defaulted to text + L1 because text + L1 is easy to generate. The right version was harder and more obviously correct once someone said it out loud.
Update: prepositions are polysemous, and don't fake a picture
Two follow-on corrections. First: one image per preposition is a lie — over means above-and-arcing and covering and more-than; on is a surface and a date and a topic. So each preposition now lists its real senses, each with its own example, and (where honest) its own diagram. The component was rebuilt around ~20 reusable archetypes — enter, arc-over, cover, more-than (a level rising past a threshold), orbit, leave-source — with dashed path-guides and arrowheads so the motion reads even between loops.
Second, and the rule that shaped it: don't fabricate a diagram for a sense that has no honest picture. "about = roughly," "on = concerning," "under = subject to" are abstract — they get the sense label and a real example, but no invented illustration. A forced diagram teaches the wrong intuition, which is worse than no diagram. The senses and examples are standard ESL meanings, not invented; the pictures appear only where one faithfully fits.