Speaking of out-of-copyright works, I checked Project Gutenberg and they do have books in various languages. There's probably some way to programmatically searc

Speaking of out-of-copyright works, I checked Project Gutenberg and they do have books in various languages. There's probably some way to programmatically search their archive to list books that are available in multiple languages - which might be suitable for creating "interlinear translations". For example, a list of all their books in Spanish: https://www.gutenberg.org/browse/languages/es https://www.gutenberg.org/browse/languages/es Or Japanese: https://www.gutenberg.org/browse/languages/ja https://www.gutenberg.org/browse/languages/ja This latter is a short list though, and they're old books with a style of writing that are not friendly for learning the language. I suppose manual curation is necessary to decide what kind of books are best for this purpose, starting with a smaller vocabulary of simple words. --- I remember in high school I discovered a book of poems by Pablo Neruda, with the Spanish original and English on pages side by side. It was a wonderful reading experience, and I learned quite a lot from it. Neruda: Selected Poems (Bilingual Edition)