Parallel System Borrowing: Parallel morphological systems due to the borrowing of paradigms

In the typology of morphological borrowing, one type has received little attention: cases where words are borrowed in several paradigmatic forms. An example of this is found in English alumnus – alumni, where Latin nouns are borrowed both in their singular and plural forms. Such borrowings lead to a coexistence of borrowed and native paradigms in one and the same language. This type of borrowing is called Parallel System Borrowing (PSB). Such patterns are wide-spread, and concern virtually all parts of morphology, including verbal inflection and pronouns. The emergence of PSB is not governed by a single sociolinguistic factor, such as the existence of learned registers (as with alumnus – alumni). In fact, it appears that some of the most spectacular cases of PSB have no relation to learned registers at all.