110. General principles of combination

In both classes of cases, however, the general principles of combination are the same—and likewise, to a great extent, the specific rules. The differences depend in part on the occurrence or non-occurrence of certain combinations in the one class or the other; in part, on the difference of treatment of the same sound as final of a root or of an ending, the former being more persistent than the latter; in part, on the occurrence in external combination of certain changes which are apparently phonetic but really historical; and, most frequent and conspicuous of all, on the fact that (157) vowels and semivowels and nasals exercise a sonantizing influence in external combination, but not in internal. Hence, to avoid unnecessary repetition as well as the separation of what really belongs together, the rules for both kinds of combination are given below in connection with one another.