Emotion
Politeness and emotions are expressed through a combination of the pitch of the voice, the intensity, the speed, the brightness, and pauses. If you speak without varying any of these, people think that you are talking like and unemotional stick. If you confess to being guilty to a crime by saying “Jitsu ha boku ga hannin desu” fluently with no pauses, there will be no emotion expressed, but if you place pauses between the phrases, “Jistuha…. bokuha… hannnin nan desu.”, then it sound like you are trying the collect the courage to confess while controlling your emotion. The placement of interjections and other “aizuchi” in speech also helps to express yourself during conversation in Japanese. Observing the “aizuchi” used in conversation between characters in drama and animation programs is one way learning how they are used.