47.2. Individual and Mass Effect.

A single act of borrowing affects, in the first instance, only the borrowing idiolect. [...] If I take a fancy to the French word ivrogne, and start to use it in my English, my idiolect is modified. The future of the language is not affected unless others imitate me, so that the newly imported word passes into more or less general usage and is transmitted to subsequent generations. This would be more probable if a number of speakers of English who knew some French were, at more or less the same time, to start using the French word in their English. Such mass importation from another dialect or language is very common, and in historical linguistics is the kind of borrowing that interests us most.

Consequently, it is customary to speak loosely of a "single" borrowing even in cases where thousands of individual acts of borrowing from one idiolect to another must have been involved. Thus we say that the Latin word vinum has been borrowed into English just twice (not thousands of times); once into pre-English, giving OE [win], NE wine; later, via Norman French, giving ME ['vijnə], NE vine. Even if the factor mentioned in the preceding paragraph were not operative, this sort of mass-statistical approach would be forced upon us by the limitations of our documentary evidence.

47.3. Conditions for Borrowing

The mere contact of idiolects A and В does not guarantee that one will borrow from the other. For a borrowing to occur, say from B to A, two conditions must be met:

(1) The speaker of A must understand, or think he understands, the particular utterance in idiolect В which contains the model.

(2) The speaker or A must have some motive, overt or covert, for the borrowing.

The first condition need hot detain us long. Our reference must be to apparent rather than genuine understanding, because in many known instances there is really some measure of misunderstanding. [...]

The second is more difficult. We cannot profit from idle speculation about the psychology of borrowers, but must confine ourselves to such overt evidence as is at hand. This may lead us to miss some motives of importance, but we can be much surer of those which we do discern. These are two in number: prestige and need-filling.

47.4. The Prestige Motive

People emulate those whom they admire, in speech-pattern as well as in other respects. [...] Upper-and middle-class Englishmen, in the days after the Norman Conquest, learned French and used French expressions in their English because French was the language of the new rulers of the country. [...]

Sometimes the motive is somewhat different: the imitator does not necessarily admire those whom he imitates, but wishes to be identified with them and thus be treated as they are. The results are not distinguishable, and we can leave to psychologists the sorting out of fine shades of difference. [...]

The prestige motive is constantly operative in dialect borrowing; it becomes important in language borrowing only under special conditions. When speakers of two different languages live intermingled in a single region, usually one of the languages is that spoken by those in power: this is the upper or dominant language, and the other is the lower. Such a state of affairs has most often been brought about by invasion and conquest, more rarely by peaceful migration. The prestige factor leads to extensive borrowing from the dominant language into the lower. Borrowing in the other direction is much more limited and largely ascribable to the other principal motive.