Today, there is ample evidence that the Japanese and Korean languages have much in common and are related languages. In Hattori, Starostin and Murayama, a topic more fully disclosed. However, it should not be forget the fact that the evidence relied on, at least not sufficiently clear lexical and phonological data. If we consider this method, we can distinguish the following basic principles of comparing two languages. First, the restoration was carried out prayaponskogo phonology, and prakoreyskogo praaltayskogo language. Second, a comparison of vocabulary and basic dictionary of languages. After all this, especially compared vocabulary on which to build language, and it was concluded that the percentage of lexical similarity is large enough so that one could assume that drevnekoreysky drevneyaponsky and languages are related.
This confirms as family of modern Korean and Japanese languages. But this method has weak points. For example, lexical and phonological similarity – this is not a sufficient argument for the claim that languages are related. It is known that these two levels of language are less stable than the structure and morphology. And so, in the first place to determine the relationship of languages to consider their structural similarity, and then move on to lexical and phonological systems. But none of the authors do not take into account. Restoring the same phonological systems of both languages can not be called true 100%, as within each group or language family has its own phonetic laws, and refer to them as it would be universal, at least, wrong.