[Footnote 50:  An Indian language of Nevada.]

[Footnote 51:  An Indian language of Oregon.]

We come now to the subtlest of all grammatical processes, variations in accent, whether of stress or pitch.  The chief difficulty in isolating accent as a functional process is that it is so often combined with alternations in vocalic quantity or quality or complicated by the presence of affixed elements that its grammatical value appears as a secondary rather than as a primary feature.  In Greek, for instance, it is characteristic of true verbal forms that they throw the accent back as far as the general accentual rules will permit, while nouns may be more freely accented.  There is thus a striking accentual difference between a verbal form like eluthemen “we were released,” accented on the second syllable of the word, and its participial derivative lutheis “released,” accented on the last.  The presence of the characteristic verbal elements e- and _-men_ in the first case and of the nominal _-s_ in the second tends to obscure the inherent value of the accentual alternation.  This value comes out very neatly in such English doublets as to refund and a refund, to extract and an extract, to come down and a come down, to lack luster and lack-luster eyes, in which the difference between the verb and the noun is entirely a matter of changing stress.  In the Athabaskan languages there are not infrequently significant alternations of accent, as in Navaho ta-di-gis “you wash yourself” (accented on the second syllable), ta-di-gis “he washes himself” (accented on the first).[52]

[Footnote 52:  It is not unlikely, however, that these Athabaskan alternations are primarily tonal in character.]

Pitch accent may be as functional as stress and is perhaps more often so.  The mere fact, however, that pitch variations are phonetically essential to the language, as in Chinese (e.g., feng “wind” with a level tone, feng “to serve” with a falling tone) or as in classical Greek (e.g., lab-on “having taken” with a simple or high tone on the suffixed participial _-on_, gunaik-on “of women” with a compound or falling tone on the case suffix _-on_) does not necessarily constitute a functional, or perhaps we had better say grammatical, use of pitch.  In such cases the pitch is merely inherent in the radical element or affix, as any vowel or consonant might be.  It is different with such Chinese alternations as chung (level) “middle” and chung (falling) “to hit the middle”; mai (rising) “to buy” and mai (falling) “to sell”; pei (falling) “back” and pei (level) “to carry on the back.”  Examples of this type are not exactly common in Chinese and the language cannot be said to possess at present a definite feeling for tonal differences as symbolic of the distinction between noun and verb.