INTONANTION
There are other suprasegmental features, besides stress, that govern appropriate English pronunciation. You will certainly remember that these other features include intonation, tone, and length. Due to its importance in native like pronunciation, the suprasegmental feature 'intonation' will be explained here. 'Intonation' means when, why and how a speaker chooses to raise or lower or sustain the pitch of her or his voice at particular points while speaking. These choices are as much a part of the grammatical system of the language as, say, using the correct auxiliary verb, or remembering when and where to place the person markers (I, you, he/she ...) which tell us who is carrying out an action; who or what is acted upon.
Intonation in American English is the tools for achieving at least five important aims: (a) expressing new information, (b) showing contrast, (c) expressing meaning, (d) showing pronunciation, and (e) showing mood or personality. Language conveys very specific information, such as how to get somewhere or what someone is doing. It can be also used beyond the exact meaning of the words to indicate how the speaker feels about what he is saying, or how he personally feels at that moment. Generally speaking, if English is not your first language, this is where you start running into difficulty. Even if you pronounce each word clearly, if your intonation patterns are non-standard, your meaning will probably not be clear. Also, in terms of comprehension, you will lose a great deal of information if you are listening for the actual words used.
Each language deals with expressing these emotional ranges and contextual importances in different ways. Some languages, such as French and other Romance languages, stress the end of a sentence, and then use word order to indicate an important change. Other languages, such as Chinese, have a pitch change that indicates different vocabulary words, and then superimpose further pitch change to change meaning or emotion. Because English has a fairly strictly fixed word order, it is not an option to rearrange the words when we want to make a point about something. Intonation in American English is the rise and fall of pitch in order to convey a range of meanings, emotions or situations, within the confines of standard grammar and fixed word order.