To the isolating languages belong most of those of southeastern Asia,—Chinese, Burmese, Siamese, Thibetan, Annamite, Cochin-Chinese, Malayan, etc. The term isolating does not necessarily imply words of one syllable, although there is a tendency in this direction since the roots are stripped of all incumbrances of a modifying nature so common in agglutinative or synthetic languages. The Chinese, Burmese, Siamese and Annamite are classed as monosyllabic, the Thibetan as half-monosyllabic, while the Malay is polysyllabic. Because languages are isolating in structure does not mean that they necessarily all belong to one family. They merely have this structural principle in common. To establish family relationships it is necessary to investigate the sets of phonetics used, the root forms, the types of ideas expressed, the composition of the sentence and various other important points included under the psychology of habit and growth forms of speech. No one of these alone is ordinarily sufficient to prove that two languages are of one common stock, since extensive borrowing of all kinds has occurred since time immemorial. Nevertheless, in point of fact, taking languages as they now exist, only those have been shown related which possess a common structure, or have together grown out of the more primitive radical stage, since structure proves itself a more constant and reliable evidence than vocabulary. But, on the other hand, since all structure is the result of growth, and any degree of difference of structure, as well as of difference of material, may be explained as the result of discordant growth from identical beginnings, it is equally inadmissible to claim that the diversities of languages prove them to have had different beginnings. In isolating languages, word order is very important, but here again the peculiar character of any tongue of this type depends upon the order selected, or the relative importance of ideas (general, specific, etc.). The employment of particles makes possible a freer word order. The _agglutinative_ languages are those which combine roots or parts of words or elements into new wholes to express other related ideas than those imparted by the single forms, or else entirely new concepts. Frequently these combinations are still separable on occasion into their original elements, or, if inseparable in their secondary meanings, their original parts with their derivations are still recognizable as such. Again, the component parts are no longer independent, but form a firmly knit whole.