1. The subject of Lexicology and the main lexicological problems

The main sources of homonymy are:

1. 
   Diverging meaning development a polysymantic word.
   
2. 
   Converging sound development of two or more different words.
   

1. 
   The process of Diverging meaning development can be observed when different meanings of some word move so far away from each other that they can be regarded as two units. The difference in spelling underlines the fact that from the synchronic point of view they are 2 distinct words even through historically they have a common origin.
   
2. 
   Convergent sound development an important factor in the creation of homonymy. The great majority of homonymy arises as a result of Converging sound development which leads to the coincidence of 2 or more word which was phonetically distinct at an early period of a language development. Another source of homonymy is borrowing. Borrowing also filled the English vocabulary with numerous homonyms. Word building also contributes significantly to the groups of homonyms and the most type in this respect is conversion. Such pairs of words as «pale-to pale. Make-to make». Homonyms of this type is which are the same in the sound and spelling but referred in different categories of parts and speech are called Lecsico-grammatical Homonyms .
   
3. 
   Shortening is a futher type of word building which increases the number of homonyms. Words made by sound imitation can also form pairs of homonyms with other words. All these sources of homonyms have one important feature in common. The hom-ms developed from two or more different words and their similarity is purely accidental. Only conversion presents an exception. A further source of hom-ms essentially differs throm all the cases given before. Homonyms has also developed from the polycemy through divergent sense development. Two or more hom-ms can originate from different meanings of the same word when for some reason the semantic structure of the word breaks into several parts. It should be born in mind that sometimes it’s very difficult to us to tell where we are having a case of polysemy or especially a case of grammatical homonymy. The problem of discrimination between polysemy and homonymy is closely connected with the problem of the basic unit of the semantic level of analysis.