The reason of appearance of borrowed words in English vocabulary

Whenever two idiolects come into contact, one or both may be modified. In face-to-face communication, either speaker may imitate some feature of other's speech; when the contact is indirect, as in reading, the influence can of course pass only in one direction. The feature which is imitated is called the model; the idiolect (or language) in which the model occurs, or the speaker of eat idiolect is called the donor; the idiolect which acquires something new in the process is the borrowing idiolect. The process itself is called `borrowing', but this requires some cautions.