Spaced repetition is a good way (perhaps even the optimal way) to get large amount of trivial memorization into your brain, but it not a good way to understand

Spaced repetition is a good way (perhaps even the optimal way) to get large amount of trivial memorization into your brain, but it not a good way to understand a complex subjects. Memorizing one word in a foreign language is not that complex, nor hard. The tricky part about learning a language is that you have to memorize thousands of words, and the trickier part is that you have to retain most of those words over a long period of time. Spaced repetition helps by finding an optimal schedule to for the exact same activity as you would otherwise.