bod vs fod vs mod
I just saw these sentences:
Dw i'n meddwl bod...
Dw i'n meddwl fod...
Dw i'n meddwl mod...
Nothing indicates for me, that the b would have a soft or other mutation, is there any dialect difference?
What is the difference? Is it because the personal pronoun? mod is for me, fod is for you and him? Not clear, because I saw the same for me with both variations (bod and fod)...
Dwi'n meddwl mod used to be "Dwi'n meddwl fy mod i" and so means "I think that I am".
Dwi'n meddwl bod-Dwi'n meddwl ei(f)/eu/ein/eich bod hi/nhw/ni/chi so "I think that she/they/us/you(formal) is/are/are/are".
Dwi'n meddwl fod-Dwi'n meddwl dy/ei(m) fod di/o so "I think they you(informal)/he are/is".
You will sometimes see all of these with bod because since the possessive has gone some people do not mutate "Bod". For example I would never say/use Dwi'n meddwl mod unless I had put the "Fy" in before hand, but I would use "Dwi'n meddwl fod" by itself with out the "Dy/ei(m).
This is just what I can think of maybe others will have a better way of explaining why.
In informal (some would claim 'lazy') Welsh you will often hear people say bo instead of mod/fod/bod:
Maen nhw'n dweud bo Siôn yn ddiog
Fe 'naeth Sioned ddweud bo'i chariad newydd yn gyfoethog
I may be wrong but I think that only first person triggers the treiglad trwynol (bod>mod), then only masculine and second person singular causes soft mutations (bod>fod) and the rest remain the same.
Dw i'n meddwl (fy) mod i'n iawn
Dw i'n meddwl (dy) fod di'n iawn
Dw i'n meddwl (eich) bod chi'n iawn
Dw i'n meddwl (ei) fod e'n iawn
Dw i'n meddwl (ei) bod hi'n iawn
Dw i'n meddwl (ein) bod ni'n iawn
Dw i'n meddwl (eu) bod nhw'n iawn