Suffixaufnahme
Suffixaufnahme is a grammatical device that occurs in some languages with case systems. It means that possessors are inflected for the case and number of the possessee as if they were adjectives. Here a few examples from Old Albic:
(1) mbar os nderos ‘the house of the man’
(2) mbaras osas nderoras ‘at/in the house of the man’
(3) mbarana osana nderorana ‘to the house of the man’
This can be nested:
(4) mbarana attorana nderomararana ‘to the house of the father of the man’
In the last example, nderomararana consists of the stem ndero ‘man’, a locative ending (marking the inalienable possession) -mas, a genitive ending -as agreeing with the genitive of atto ‘father’, and the allative ending -ana ‘to’ agreeing with the ending of mbar ‘house’.
For more on suffixaufnahme, and natlangs showing this phenomenon, see Wikipedia: Suffixaufnahme.