What a native speaker knowns.

Native speakers know how to say a word – that is how to pronounceit. This knowledge is made up of three areas, sounds, stress and intonation.

 Sounds
On their own sounds of a language may wellbe mainingless. If you say /t/ (the lines show that this is phonetic spcript) a few times, e.g. ‘tu, tu, tu’ iit will not mean very much in English. Neither will the sounds /k/, /a/, or /s/. but if we put all these sounds together in a certain order we end up with the word ‘cats’ – and that does mean something.
All words are made up sounds like this , and speakers of a language need to know these sounds if they are to understand what is said to them and be understood in their turn. Some of the promblems that speakers of english as a foreign language have are precisely because they have difficulty wiyh individual sounds – for example the Spanish speaker who says ‘bery’ istead of ‘very’ or the Japanese speaker who says a word which sounds like ‘light’ instead of the intended ‘right’.

 Stress
When they use a word native speakers know which part of that word should receive the heaviest emphasis. For example, in the word ‘photograph’ not all the parts are of equal importance. We can divide the word into three parts : ‘pho’, ‘to’, and ‘graph’. Competent speakers of the language will say theword like this, ‘PHOtograph’, stressing the first syllable. The situation changes with the word ‘photographer’ where the stress shifts to the second syllable, i.e. ‘phoTOgrapher’. Stress in words also changes depending upon a word’s grammatical function: ‘perMIT’ is a verb, but ‘PERmit’ is a noun, and the same is true of the words ‘imPORT’ and ‘Import’, for example.
The changing use of stress in sentences is also one of the areas of knowledge that competent language speakers have. For example if I say ‘I can RUN’ I am peobably only talking about my ability to run. But if I say ‘I CAN run’ I am probably stressing the word can because somebody is suggesting that I am not able to run and I am vehemently denying it. In the same way if someone said to you ‘is this your PECcil?’ it might well be a simple question with no hidden meaning, but if the question was ‘Is this YOUR pencil?’ this might suggest that there was something very suprising about your ownership of the pencil.
Native speakers of a language unconsciously know about stress and how it works. They know which syllables of words are stressed and they know how to use stress to change the meaning of phrases, sentences and questions.

 Intonation
Closely connected with stress is intonation, which means the tune you see when you are speaking, the music of speech.
Intonation means the picth you use and the music you use to change that pitch. Do you use a high pitch when you say a word? Does your voice fall or rise at the end of a sentence? For example, if I say ‘You’re from Australia, aren’t you?’ startingn my question at the medium pitch of my voice range and dropping the pitch at the end of the sentence (on ‘aren’t you’) this will indicate to other competent speakers of English that I am merely seeking confirmation of a fact about which I am almost completely certain.