If the original introducer or a later user has good command of the foreign language, he may speak the foreign form in foreign phonetics, even in his native context. More often, however, he will save himself a twofold muscular adjustment, replacing some of the foreign speech-movements by speech-movements of the native language [...] This 'phonetic substitution' will vary in degree for different speakers and on different occasions [...]
- Bloomfield (1935), a pag.445

The historian will class it as a type of adaptation, in which the foreign form is altered to meet the fundamental phonetic habits of the language. In phonetic substitution the speakers replace the foreign sounds by the phonemes of their language.
- Bloomfield (1935), a pag.446