а+е=ә, о+е=ө, ұ+е=ү, ы+е=і (Mathematical model and oscillograms of vowel sounds of the
Kazakh language are given in the Appendixes b.a and b.b). These relationships show that two letter
combinations can be used to indicate allophones. Such a method is also used in other languages. For
example, in English the sound ш is indicated by a combination of letters s and h. In addition, we
have built a body of Kazakh language, which contains 100 million letters of our current alphabet
and done a research about the frequency of letters and letter combinations with the help of computer
programs (The frequencies of letters in the text body of Kazakh language are given in Appendix c).
The results of these studies were needed to determine which letter and which letter
combination can efficiently indicate sound (not extending the length of the words). The results also,
before the conversion of Kazakh writing to the new alphabet, will help to create a new spelling
dictionary without the letters ё, и, ц, ч, щ, ь, ъ, э, ю, я, which will be excluded from the current
alphabet (Appendix d shows examples of terms written in only Kazakh letters of the current
alphabet).