Tabito

Here's a sentence that means “In Kyoto, I took a lot of photos” (Genki II, 15-IV):

京きょう都とでたくさん写しゃ真しんを撮とりました

If you had a flashcard app that presented you with this English translation and asked you to produce the Japanese, there’s a few variations you’d want to be able to handle:

"たくさん" ("lots") can function as an adverb so you want to allow: 京きょう都とで写しゃ真しんをたくさん撮とりました
Of course you want to allow the informal conjugation of 撮とりました, so: 撮とった
Oh, sometimes IME will convert たくさん to kanji: 沢たく山さん
And in fact you want to allow any combination of kanji and kana.
By the way, you'll want to treat hiragana and katakana as equivalent (again, IME).

Tabito is a small TypeScript app that lets you specify the variations of the sentence you want to allow and then to match user input to this. Try it below! Type various parts of the sentence above with the variations described and see how close you get.

Matches will go here

For reference, if you type in misordered clauses, it looks like this:

with the green box indicating that this “piece” actually should come first. Once you type in the entire sentence correctly, the background will celebrate:

And here’s a full editing session: