1. Get a frequency list. The most common word's rank is 1, the second is 2, etc. [0]
2. Then use your favorite Spaced Repetition Software (such as anki) to learn the words in that order.
3. Define a sentence's difficulty as the maximum rank over all its words. You could refine it by adding tie-breakers but I think it doesn't matter. Then sort the sentences in order of difficulty.
1. Get a frequency list. The most common word's rank is 1, the second is 2, etc. [0]
2. Then use your favorite Spaced Repetition Software (such as anki) to learn the words in that order.
3. Define a sentence's difficulty as the maximum rank over all its words. You could refine it by adding tie-breakers but I think it doesn't matter. Then sort the sentences in order of difficulty.
[0] See https://en.wiktionary.org/wiki/Wiktionary:Frequency_lists