learn by rote
To use repetition to memorize something, as opposed to acquiring a full or robust comprehension of it. A noun or pronoun can be used between "learn" and "by." Learning by rote has been proven by many studies to be nearly useless in the long-term retention of information. There are so many characters in the Japanese alphabets that I have to learn them by rote.
learn something by rote
Fig. to learn something by memorizing without giving any thought to what is being learned. I learned history by rote; then I couldn't pass the test that required me to think. If you learn things by rote, you'll never understand them.