Do Borrowed Words Change or Do They Remain the Same?
The eminent scholar Maria Pei put the same question in a more colourful way: "Do words when they migrate from one language into another behave as people do under similar circumstances? Do they remain alien in appearance, or do they take out citizenship papers?" 
Most of them take the second way, that is, they adjust themselves to their new environment and get adapted to the norms of the recipient language. They undergo certain changes which gradually erase their foreign features, and, finally, they are assimilated. Sometimes the process of assimilation develops to the point when the foreign origin of a word is quite unrecognisable. It is difficult to believe now that such words as dinner, cat, take, cup are not English by origin. Others, though well assimilated, still bear traces of their foreign background. Distance and development, for instance, are identified as borrowings by their French suffixes, skin and sky by the Scandinavian initial sk, police and regime by the French stress on the last syllable.
Borrowed words are adjusted in the three main areas of the new language system: the phonetic, the grammatical and the semantic.
The lasting nature of phonetic adaptation is best shown by comparing Norman French borrowings to later ones. The Norman borrowings have for a long time been fully adapted to the phonetic system of the English language: such words as table, plate, courage, chivalry bear no phonetic traces of their French origin. Some of the later (Parisian) borrowings, even the ones borrowed as early as the 15thc., still sound surprisingly French: regime, valise, matinee, cafe, ballet. In these cases phonetic adaptation is not completed.