In Genoese, a number of words formed etymologically with the Latin prefixes con- and in- (whether directly inherited or newly formed in Genoese by analogy) may either retain the nasal consonant of the prefix or assimilate it to the following consonant. This gives rise to pairs such as construe ~ costrue “to build”, inluminâ ~ illuminâ “to illuminate”, or inmanegâ ~ immanegâ “to handle”. Both forms are in use and equally correct.

The same applies to pairs such as inludde ~ illudde “to delude”, inmenso ~ immenso “immense”, or inlustrâ ~ illustrâ “to illustrate”, where the initial in- is not etymological but results from the dissimilation of the original consonant clusters.