Does Welsh have a "plural of singulative" like (Revived) Cornish does?
There, you have e.g. gwydh "trees", gwedhen "a tree" and also gwedhennow "(individual) trees" -- the difference with the collective being, as I understand it, that the plural of the singulative emphasises the individual nature of the elements.
(It's clearer in things such as holanennow "grains of salt" versus holan "salt".)
Is there a coedennau or the like in Welsh as well for when I view the trees individually rather than collectively?
There are some traces of that in some words, perhaps. For example:
- gronyn - a grain or particle
- gronynnau - grains, particles (usually as several or many individual items)
- grawn - grain or particles (as in a collection or handful, etc, of grain)
You would probably harvest or sow grawn, but empty a few gronynnau out of your boots afterwards.