"I think that the best wine is in France."
Translation:Dw i'n credu taw yn Ffrainc mae'r gwin gorau.
If the sentence was an unemphatic one:
- Mae llawer o win da yn Ffrainc - There is a lot of good wine in France
we would use a bod... form to introduce it after 'I think that':
- Dw i'n meddwl bod llawer o win da yn Ffrainc.
But if we want to emphasise that it is in France that we find the best wine, we have to move that to the front of the Welsh sentence:
- Yn Ffrainc mae'r gwin gorau - The best wine is in France.
To keep that emphasis, we have to keep the verb in the middle of the clause intact when we put 'I think that...' on the front. We can't do that if we use mod/fod/bod, so we have to use the particle taw/mai to make the link instead:
- Dw i'n meddwl mai yn Ffrainc mae'r gwin gorau (mai or taw - it makes no difference)