When speaking, people generally raise and lower the pitch of their voice, which form pitch patterns. They also give some syllables in their utterances a great degree of loudness and change their speech rhythms. These phenomena are called intonation. Intonation does not happen at random but has definite patterns which can be analyzed according to their structures and functions. Intonation is used to carry information over and all it is expressed by the words in the sentence.

Intonation is very important in expressing meanings and especially in showing our feelings, for example: surprise, anger, disbelief, gratitude…When communicating, learners cannot usually show their feeling and pronounce sentences with a correct intonation, either.

Listening and speaking are essential communicative skills in most interactive situations that learners of a foreign language have to acquire at the very early age of their learning course. It is important to note that in communicating, English intonation patterns are the ones that have not occupied much attention of the Vietnamese learners of English. When transmitting a thought, manifesting an intention, a feeling or displaying information they do not always focus on kinds of intonation and how it should be modified. Thus how to convey the feelings or meanings successfully with appropriate intonation patterns of performance may still be a problem which prevents learners from performing an effective communication.

General 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 word used.

Linguists have used various ways for the notation of the pitch movements of the utterances performed by speakers in connected speech. For a simple representation of the tone used for a certain utterance, the arrows showing the downwards or upward direction of the pitch movement are used just to mark the tonic syllable. For example, the utterance She went to Paris yesterday will have the tonic syllable marked with the arrow downward as follows:

She went to Paris yesterday 

Or the listing of languages that a person can speak will be represented with the pitch movement as follows:

He can speak English, Spanish, Arabic and Italian.

For a more detailed notation of intonation in English, we can make use of various types of representation. Halliday [12, p.21 - 22] uses simple line to show the intonation contour of the pitch movements. For example, the falling tone used for the utterance I’m from Canada will be represented as follows: 

Tonic: falling

The tonic of tone 1 falls, and ends on a low pitch. It may start at any point from mid-low upwards; the neutral type (see secondary tone) starts mid or mid-high. There is also great variation in the pretonic; the neutral type has an even contour, which often remains fairly level at about mid or mid-high pitch. This gives a basic form in which the tonic starts at about the same pitch as that where the pretonic ends. 

Basic form:      

 

Example:

//1 I’m    from   Canada//

 

Or the high rising tone used for the utterance Do they take the car when they go abroad? will be represented as follows:

Tone 2

Tonic: high rising or falling-rising(pointed) 

In both cases the tonic rise to  a high pitch and the rise is fairly steep: The high rising form is the neutral type; it often starts about mid-low. There are also two types of pretonic; the neutral one: called 'high' (see secondary tone), may take various forms; but the basic form can be taken to be high level. 

Basic form: 

Example:

        //2 do they       / take the  / car when they /go a /broad //

Halliday’s notation is easy to understand and it can easily show the intonation contour that goes upwards or downwards in different tones. However, this type of notation cannot show the details of the prehead such as the unstressed and stressed syllables. 

 

However, the description of the learner’s speech mentioned in these studies is somewhat prescriptive although the author tried to substantiate the learners performance with the recording and the assessment of the native speakers.