It'd be a better example of an exception if it unambiguously started with a vowel. This is sort of the reverse of the case I pointed to above, where "habito" does start with a vowel, or rather it almost does, enough to trigger the same changes.
> Before vowels and aspirates, it is reduced to co-; before -g-, it is assimilated to cog- or con-; before -l-, assimilated to col-; before -r-, assimilated to cor-; before -c-, -d-, -j-, -n-, -q-, -s-, -t-, and -v-, it is assimilated to con-, which was so frequent that it often was used as the normal form.
I and J aren't different letters in Latin, but they are different kinds of sound, if sometimes only hazily different. Same goes for U and V. By modern convention we have convention and conjecture; the hazy difference seems sufficient to explain why the Romans left us every variety of the compound, from coniicio through conicio to coicio. A naive analysis (the most I can really do) would say that coniicio comes from someone who sees iacio as starting with a consonant, coicio comes from someone who doesn't, and conicio is a reduced form of coniicio.
It'd be a better example of an exception if it unambiguously started with a vowel. This is sort of the reverse of the case I pointed to above, where "habito" does start with a vowel, or rather it almost does, enough to trigger the same changes.
https://www.etymonline.com/word/com-
> Before vowels and aspirates, it is reduced to co-; before -g-, it is assimilated to cog- or con-; before -l-, assimilated to col-; before -r-, assimilated to cor-; before -c-, -d-, -j-, -n-, -q-, -s-, -t-, and -v-, it is assimilated to con-, which was so frequent that it often was used as the normal form.
I and J aren't different letters in Latin, but they are different kinds of sound, if sometimes only hazily different. Same goes for U and V. By modern convention we have convention and conjecture; the hazy difference seems sufficient to explain why the Romans left us every variety of the compound, from coniicio through conicio to coicio. A naive analysis (the most I can really do) would say that coniicio comes from someone who sees iacio as starting with a consonant, coicio comes from someone who doesn't, and conicio is a reduced form of coniicio.