Learning with spaced repetition. Intervals of time between seeing the same card is increased or decreased depending on whether the answer was known or not.
Chinese learner will have to learn pinyin as well. Pinyin is an official romanization system for Chinese characters. The four tones are indicated by accent marks which cannot easily typed in with English keyboards. Wise Cards will convert ma1, ma2, ma3, ma4 to mā, má, mǎ, mà