A phonetic mistake involves a different realisation of a phoneme, so that the speaker uses an allophone of a particular phoneme within an utterance. This may occur due to the speaker's linguistic background and does not change the meaning of the word.
The rhotic /r/ involves the pronunciation of the /r/ phoneme after a vowel in certain varieties of English.
The rhotic /r/ is commonly used in the American variety of English.
Change in the tone of a word is a common linguistic phenonmenon in most languages. However, in certain langauges, a change in tone can determine the meaning of a word' (Roach, p. 154). Such languages are termed tone languages'. English is not a tone language, since whether one utters the word yes' with a high level or a low level tone (yes' or yes'), the meaning of the word still remains unchanged. In contrast, tone languages such as Thai and Vietnamese employ a different pitch in order to change the meaning of a word. For instance, in the Kono language, words which contain the same phonemes but a different tone mean different things, so that buu means horn', but buu stands for being cross' (Roach, p. 154).
Roach (1983) describes four functions of intonation as he explains how speakers employ intonation to communicate effectively. The first is the attitudinal function of intonation, which allows people to convey their emotions through a particular tone. For instance, if one can say Good luck' in such a way as to convey genuine enthusiasm for someone's prospects, or else utter the same words in a sarcastic way which betrays one's envy for that other person. ...