"I have gone to the park."
Translation:Dw i wedi mynd i'r parc.
That is generally conveyed better by using the simple past tense, or by using the simple past tense of gwneud as an auxiliary:
- Es i i'r parc (simple past of mynd)
- Gwnes i fynd i'r parc (simple past of gwneud used as auxiliary)
Iawn, diolch. Could "Gwnes i" also be "Gwnais i", or is that a different tense?
Oddly enough, gwnais does not get used - gwnes i is the common colloquial form, as are des i, es i (from dod, mynd), but the more formal forms of each of them are quite different. On the other hand, it is quite common to hear people pronounce the -ais verb endings as /-es/.