Korean Sentence Analysis

This is a fairly simple app using Next.js and the AI SDK to parse out grammar and vocabulary details from given Korean sentences. For example, given "한국어는 공부할 만해요.", it will translate each word (한국어: Korean), highlight a few grammar points (-할 만하다: to be worth doing), and translate the sentence in full ("Korean is worth studying.").

This will locally-cache the AI results to avoid repeated calls, but only while the page is open. Sometimes the AI API does not return the full expected object causing an error — trying again usually works.

Read my writeup & see some screenshots: https://ryelle.codes/2025/08/building-a-korean-grammar-breakdown-tool-with-ai-and-next-js/

Try it out!

You'll need an OpenAI API key. Once you have it, create a file .env.local and add the key like this:

OPENAI_API_KEY=yourkeyhere

Now you can install the dependencies and start the app.

npm install
npm run dev

Open http://localhost:3000 with your browser to see the result.