In written language, our thoughts and our speech are represented by visual symbols to convey the meaning of what we are writing and saying. In an alphabetic language like English, the 'visual symbols' are letters. These are combined together into words which have meaning for us. Sometimes these 'letters' correspond to our perception of the sounds we hear in the words we speak. Sometimes they do not.
In the 17th century spellings of English words were 'set in stone' when the first dictionaries were written. These spellings have not changed over time. It is because they have not changed over the years, that we can read books written in previous centuries.
In some languages each letter corresponds to a specific sound. Learning to read and write is fairly easy in these languages. But the English language has only 26 letters in its alphabet and 44 different sounds are defined as standard in British Received Pronunciation. There is no single correspondence between each letter and each sound.
Sometimes a combination of letters corresponds to single sound e.g. 'ch' as in 'chip'. Sometimes the same letters correspond to a different sound, e.g. 'ch' in 'chemist' or 'ch' as in 'chef'.
Sometimes a single letter represents more than one sound, e.g. 'a' in 'cat, father, baby'. Each 'a' corresponds to a different sound. The letter 'y' is pronounced differently in 'mummy, my, yet, gym' as well as being part of vowel graphemes in 'ay (day), ey (grey), oy (toy), ey (donkey)'. This makes learning to read and write in English very difficult. Sometimes we need to know the meaning of the word before we can decide how to pronounce it, e.g. 'row, row; wound, wound; beak, bread, break'
We may learn all the different pronunciations of the letters and letter combinations, and still this will not tell us to how to choose the correct pronunciation of a word without knowing what it means in the context of the written message. We need to relate the spelling of the word, i.e. its written symbols, to something else we already know, i.e. what the word means.
Let's consider letter symbols too. If we think of the first letter of the alphabet, 'a' or 'A, we can see straight away that it has two written symbols. (In actual fact 'a' has more than two symbols because children do not write the small letter 'a' in this particular type-font. They use the shape of 'a' as that in the Sassoon Primary Infant, Century Gothic or Comic Sans fonts.)
The first symbol is lower case on the keyboard, or a 'small' letter. The second symbol is upper case on the keyboard, or a 'capital letter'. The capital letter is only used at the beginning of a sentence or the beginning of a name, and its corresponding sound is the same as that of the small letter. We would pronounce 'cat, baby, father,' exactly the same when written in capital letters 'CAT, BABY, FATHER'.
So the capital letters do not correspond to different sounds and they do not add to our 26 letters in the alphabet.
If we pronounce the words 'car' and 'father', 'down' and 'about', 'form' and 'pawn', 'royal' and 'boil', 'girl' and 'curl', 'hair' and 'stare', 'year' and 'deer', we can hear the same sound for the vowels in each pair of words, but the spellings are different.
How do we learn which spelling goes with which sound in which word? We can only do that if we know the meaning of the word and we have this extra information to help us. The sound of the word alone will not tell us how to spell it. We need to visually memorise it also.
If we say the alphabet aloud, we say 'ay, bee, see, dee, ee, eff, gee, aich, I, jay, kay, ell, em, en, oh, pea, queue, are, ess, tee, you, vee, double-you, ex, why, zed'. We notice that these are not the same as the sounds of the letters of the alphabet. They are something different. In fact they are the names of the letters of the alphabet.
When someone asks us to spell the word 'dog', we will probably say 'dee, oh, gee'. This is because, as adults, we use the letter names to say the spellings of words. These letter names are not at all like the sounds in the word 'dog' and children have to learn these letter names too so that they may talk about the letters in conversation with other people.
Also, some of the sounds corresponding to the consonant letters of the alphabet are impossible to articulate without an audible sound on the end, e.g. 'b' and 'd', 'p' and 't'. This is because the smallest units of speech that humans use in normal conversation are syllables, i.e. they always contain a vowel.
(There are some continuant consonants that can be easily pronounced e.g. 'sssss' (the hiss of a snake) or 'shhhh' (be quiet) or 'mmmmmm' (yummy) or 'ffffff' and 'rrrrrr'.)
Human speech is a continuous stream of ever changing sound and it is very difficult to segment (split up). It is not made up of separate sounds which we are consciously aware of when we are speaking and listening. No one needs to be aware of separate sounds in speech until they are learning to read and write. At this point the letters (symbols) we write need to be assigned to either the sounds within speech or a complete word. This is when sounds are classed as vowels or consonants depending whether we say them with an open mouth whilst we expel air (vowels), or we make actions with our tongues, teeth and lips to say consonants.
We have begun by using the simplest CVC (consonant-vowel-consonant) words which children understand, e.g. 'cat, dog, hat, box'. Children know what these words mean from their use in spoken language and picture books. Initially, each noun is introduced in our early books with a picture to ensure that the children know the meaning of the word. When each noun is split up into the sounds corresponding to the letters, children are able to learn letter/sound correspondences. They can say each sound and write each letter.
In our first books these nouns are joined by the prepositions, 'on, in, and' and the indefinite article 'a'. There are pictures to ensure that children understand the meanings of 'in, on, and'. These words may then be split up into the sounds of the letters so that children learn the letter/sound correspondences.
We introduce the word 'the' early in the books, because it is impossible to write anything meaningful without it. Children very quickly learn how to pronounce it as a whole word and they soon recognise it every time they see it.
The vocabulary used in our books means that we introduce the phonic progression gradually and sequentially. We also introduce 'common exception' and 'high-frequency' words at each stage. Children are not overwhelmed by too many new ideas at once. They gain confidence when reading successfully, and this gives them the motivation to learn more.
Our aim is to make reading enjoyable for children and to give them pleasurable experiences which they want to repeat. Then, as their vocabulary grows, they have the necessary skills to read the new words they meet in the wider school curriculum.