Perhaps someone could verify this for me since these grammar books that I have only go over the progressive tense in Cornish with direct objects that are pronouns. For instance, "I was kissing her." In this case, these grammar books say that the direct object is actually a possessive adjective like "his", "your", etc. placed before the verbal noun, much like what goes on in Irish. I am assuming that all other direct objects which aren't pronouns must be in the genitive case as they are in Irish too. For instance, "I am petting the dog." and "I am washing the car." Does anyone know if this is correct? I imagine it must be since that seems to be a feature of Celtic languages, but perhaps P-Celtic and Q-Celtic languages have some differences in terms of the progressive tense that I am not aware of. Hmmm.
Now, the Welsh noun case system broke down more than a thousand years ago, and if I'm not mistaken, this was a development across the whole of Brythonnic (P-Celtic). This means that the genitive case of the noun is identical in form to the nominative case, and so in a sentence like mae'r ceffyl yn bwyta'r gwair the genitive relationship between the nouns bwyta ("eating") and y gwair ("(of) the grass") isn't as obvious as it is in the equivalent sentence in Irish (genitive constructions work exactly the same way in Welsh as they do in Irish, except for the actual form of the word, e.g. hata an fhir = het y dyn = the man's hat). However, the case system did survive in pronouns, hence ei fwyta instead of *bwyta fo.
If Cornish works in the same way as Welsh, and I suspect it does, then for learners only if the object of the verbal noun is a pronoun does it present difficulties because, being a possessive adjective, it seems anomalous; while noun objects, although technically also in the genitive, can simply be added after the verbal noun without worrying about changing their form, since the genitive and nominative look exactly the same.
Wow. Thanks for this information, Coligno. That does definitely make things easier. I'll have to do some research to see if this has in fact happened in Cornish as well, but I am suspecting it is as you said. :)
This is a feature of Celtic grammar in general. The reason it happens is because the progressive tenses are formed with the verbal noun. The verbal noun, although expressing the action of a verb, functions grammatically as a noun, and of course nouns cannot take subjects or direct objects in the same way verbs can. Nouns relate with other nouns through prepositions or through genitives, hence the use of a preposition to link the "subject" to the verbal noun (<em>tá an capall ag ithe</em>/<em>mae'r ceffyl yn bwyta</em>) and the genitive to link the "object" (<em>tá an capall ag ithe an fhéir</em>~<em>tá an capall á</em> (<<em>ag a</em>) <em>ithe</em>/<em>mae'r ceffyl yn bwyta'r gwair</em>~<em>mae'r ceffyl yn ei fwyta</em>)(the possessive adjectives can be thought of as the genitive case of the personal pronouns).