The prosodic (or suprasegmental) characteristics of speech are those of pitch, loudness and speed (or tempo, or speech rate; its inverse is the duration of the constituent segments). These combine together to make up the rhythm of speech, and are combined in turn with stretches of silence (pause) to break up the flow of speech.
To some extent prosodic characteristics are the same in all languages. It is probably true of all human societies that speakers speed up when they are excited or impatient and slow down when they are being thoughtful or serious. We all speak more quietly than normal when we do not wish to be overheard. We all have to speak more loudly t be herd over a distance or in noisy conditions (unless, of course, we can use modern technology to transmit and amplify the signal for us). But it is clear that different languages also regularly differ in their prosodic characteristics. Simply transferring the prosodic patterns of one's mother tongue or L1 to a foreign language or L2 (such as English) contributes to making you sound foreign, and may quite possibly lead to your being misunderstood by other speakers. Stress is realised by a combination of loudness, pitch and duration. Some languages use stress placement lexically (=to distinguish between different words in the dictionary). For example, the Greek words πολι ['poli] and πολύ [po'li] differ in meaning. The first means "city", the second means 'much, very'. The difference of meaning depends entirely upon the location of the stress, and involves no difference in the consonant and vowel sounds. Other languages do not use stress lexically: in French there are no pairs of words of different meaning distinguished by stress placement. In English there are a few pairs of words distinguished just by stress, for example 'billow and be'low or 'important (noun) and im'port (verb). However the English habit of weakening unstressed vowel means that most pairs of words differing in stress often also have differences in their vowel sounds, so that the distinction is not carried by stress alone. Nevertheless, English is, like Greek, a stress language: stress is an important part of the spoken identify of an English word. A complicating factor is that differences of stress in English are largely signalled by pitch movements. Tone is another prosodic characteristic, being realised mainly by differences in the pitch of the voice (.g. high level, mid level, low level, rising or falling). A high pitch results from the relatively rapid vibration of the vocal folds in the larynx, a low pitch from a relatively rapid vibration of the vocal fold in the rate of vibration is heard as the rising pitch, a slowing down as a falling pitch. In a level pitch the vocal folds vibrate at a constant rate. Some languages use tone lexically. For example, in Tahi the syllable [kha:] has different meanings depending on the tone with which it is said. With tone 1 (a mid level tone) it means 'to be stuck'. With tone 2 (low level) it is the name of a plant 'galingale'. With tone 3 (falling) it means 'value', with tone 4 (high level) 'to trade', and with tone 5 (rising) 'leg'. In Mandarin Chinese [ma] with tone 1 (high) means 'mother', with tone 2 (rising) 'hemp', with tone 3 (low fall-rise) 'horse', and with tone 4 (falling) 'to scold.'. In Zulu, [i'nanga] inyanga with high tones on the first and last syllables means 'moon, month', but with high tone only on the first syllable means 'traditional practitioner, herbalist'. Some languages have tonal differences, but only on stressed syllables. In Norwegian ['bønər] has two possible meanings. With one tone on the stressed syllable it means 'peasant'' (bønder), but with another 'beans' (bønner). Tokyo Japanese make lexical use of what is known as pitch accent, which is manifested as a sudden drop in pitch immediately after the place in the word where the accent (if any) is located. The segmental string [haçi] hashi with no accent means 'end, edge'. With an accent on the first syllable it means 'chopsticks', second syllable is much lower pitched than the first, but the difference between 'bridge' and 'end, edge' is manifested in the pitch of the syllable at the beginning of the following particle, e.g. in the [ga] of hashi-ga, which is low pitched for 'bridge' but not for 'end, edge'.