But this distinction, though one of high value, theoretically and practically, is not absolute. Thus:

a. Suffixes come to have the aspect and the use of primary which really contain a secondary element — that is to say, the earliest words exhibiting them were made by addition of secondary suffixes to words already derivative.

b. Sundry examples of this will he pointed out below: thus, the gerundival suffixes, tavya, anīya, etc., the suffixes uka and aka, tra, and others. This origin is probable for more cases than admit of demonstration; and it is assumable for others which show no distinct signs of composition.

c. Less often, a suffix of primary use passes over in part into secondary, through the medium of use with denominative "roots" or otherwise: examples are yu, iman, īyas and iṣṭha, ta.