Intonation is the melodic and rhythmic pattern of speech. Different words and sentences have different intonations, which can convey different meanings. For example, think of the difference between the English sentences “You watched the video.” and “You watched the video?” The main sound difference between these sentences is the intonation at the end of the sentences.
Intonation is important to make Japanese utterances sounds natural. Even if the pronunciation of individual words is good, the wrong intonation may make you hard to understand, or you may be misunderstood. Watch the video below to learn more about intonation, particularly in Japanese.