Reading as a skill at the very basic level requires the reader to 'sound' out the written word into teh sound that it makes.
Each word may be composed of a combination of any of the forty four recognised phonemes of English language. These are independently vowel and consonant phonemes and are quite independent of each other. A detailed account of the sounds routinely used in English language can be found easily on the web http://facweb.furman.edu/~wrogers/phonemes/
In Hindi ( Devnagiri script) this is even worse- each set of grouped phonemes has 5 or 4 for the final two rows, sounds and each of these sounds can be combined with any of the twelve vowel sounds ( maatras) resulting in 68x12 sounds. These combinations are palced spatially all around the consonant sounds- uh sound is denoted by a complete consonant, aah sound by a straight line following it, the short i sound is denoted by a maatra that is placed in front of the consonant it modifies while the long ee sound is denoted by one that follows the consonant it modifies. These are both looped above the zone of active reading. Consider the short u as in butcher that is like a comma under the consonant, and the loong oo sound that is placed in the opposite direction also under the consonant. This spatial jig zaw can be quite confusing for a new reader or for a reader who has reading difficulties.
Each written symbol, then denotes a sound for the reader. These are eventually sounded out in the head as a part of the decoding process, and assigned a combination sound or word. Thus, seeing a written word kicks into motiona complex set of neural activities starting woth actually perceiving the written word, following it with a decoding process and mental sounding out, thereafter comes synthesis of these phonemes into a word.
Once the mind has arrived at a word, it searches its data base, so to speak for all meanings ut has denoted to this decoded combination of phonemes in the past learning experience, and picks teh meaning that is closest in the context. Infact, a child with good phonemic concepts can read fluently and correctly without even knowing the meaning of the words.
One look at http://www.auburn.edu/~murraba/spellings.html shows just how complicated rreading really can be! Imagine that ear has several sounds it can denote- ear itself, hear, heart. And if heart is read HAArt, why must cart not be ceart? And so on!
This mess and confusion prompted George Bernard Shaw to propose an all together new and presumably more appropriate system of language! He proposed that sounds and letters should correspond without overlap. Thus, in his alphabet k could not be represented by c, or by ch. He joked that ghoti is the way English spells what we read as fish!( gh from laugh, o from women, ti from nation. ) In fact several'i' words could as easily be written as 'ai'! TAIM ( Ta- im) Time!
The Devnagiri script for Hindi is much more scientific in this regard. Each sound is represented by a single alphabet. However, the complexities of the added vowel signs all around the consonants complicates the written word.
Study of the brain in the reading task has shown that only the visual cortex is stimulated if the printed symbol is a simple circle/ line etc. This changes dramatically when the printed symbol has a meaning- the alphabet or the pictographs. This task stimulates the visual association areas along with several areas in the language and the analysis related parts of the brain. This is further expanded to include association areas in the latter fields when the symbols are strewn together to form words and words are strung together to form sentences.
The children who are unable to form these associations find the initial decoding difficult. They may be seeing a symbol and thinking another one. It is instructive to try this little test from a wonderful website devoted to understanding these children.
Try this link.... for a reading experiment
Reading comes easy to some. Many others struggle with this task well into adulthood. These are not people with subnormal intelligence. They are people who are wired differently. We, as parents and teachers have the responsibility to connect with them, and see that the decoding can happen easily... without emotional trauma and burden that often accompanies the classroom experiences of these specially enabled children. they will often be highly talented and versatile. they are not lazy and they are not stupid. they are different. Respect that difference!