[…] loss of what had constituted the material of a language was an appreciable element in that constant change and development which we called its growth. Even such a process of subtraction is fairly enough to be reckoned as a part of growth of organic beings consists in removal as well as in resupply […] the loss might consist either in the disappearance of complete words from a vocabulary, or in the disappearance of the signs of grammatical distinction.
- Whitney (1875), a pag.98

[…] there are [...] two principal ways in which loss can occur. In the first place, the disappearance from before the attention of a community of the conceptions designated by certain words occasions the disappearance of those words. If anything that people once thought and talked about comes to concern them no longer, its phraseology goes into oblivion- unless, of course, it be preserved, as a memory of the past, by some of those means which culture supplies […] But, in the second place, words are crowded out of use, and so out of life, by the coming into use of other words which mean the same thing, and which for some cause, definable or not, win the popular favor, and supplant their predecessors.
- Whitney (1875), a pag.99-100

The English is, in truth, of all the languages of its kindred the one which most remarkably illustrates the loss of formal grammatical distinction by sinthetic means; there is no other known tongue which, from having been so rich in them, has become so poor; none which has so nearly stripped its root-syllables of the apparatus of suffixes with which they were formerly clothed [...] Much of the loss has been the work of the last few centuries; and there is no difficulty in pointing out causes which have at least quickened it. When men learn a strange language, by a practical process, they are apt especially to make bad work with its endings; if they get the body of the word, its main significant part, intelligibly correct, they will be content to leave the relations to be understood from the connection.
- Whitney (1875), a pag.105