Mae rhai arddodiaid yn rhedeg i ddynodi person a rhif. Mae 'wrth' yn un ohonyn nhw. Dyma ffurfiau rhediadol 'wrth':
Rhediad Wrth
| wrthyf i | from me | wrthyn ni | from us |
| wrthyt ti | from you | wrthych chi | from you |
| wrtho fe | from him | wrthyn nhw | from them |
| wrthi hi | from her |
Mae rhai ffurfiau berfol yn cael eu dilyn gan wrth:
| Adrodd wrth [to relate to] |
Adroddodd e'r stori wrthi hi | He related the story to her |
| Cyfaddef wrth [to admit to] | Cyfaddefodd y cwbl wrth yr heddlu | He admitted everything to the police |
| Dweud wrth [to say, to tell] | Ddwedodd e wrthych chi? | Did he tell you? |
| Glynu wrth [to stick to] | Mae e'n glynu wrth ei stori | He is sticking to his story |
Mae rhai ansoddeiriau'n cael eu dilyn gan wrth:
| cas wrth [nasty to] |
Paid â bod yn gas wrthyf | Don't be nasty to me |
| caredig wrth [kind to] | Mae hi'n garedig wrth bawb | She is kind to everyone |
| creulon wrth [cruel to] | Mae e'n greulon wrthynt | He is cruel to them |
| dig wrth [angry with | Wyt ti'n ddig wrtho o hyd? | Are you still angry with him? |
| Glynu wrth [to stick to] | Mae e'n glynu wrth ei stori | He is sticking to his story |
Enghreifftiau
| Ydych chi wedi dweud wrthi hi eto? | Have you told her yet? |
| Dwy i ddim wedi cyfaddef wrthyn nhw | I haven't admitted to them |
| Mae pawb wedi digio wrtho fe | Everyone is annoyed with him |
| Mae rhaid iddi hi adrodd y hanes wrthym ni | She has to tell us the story |
Sylwch ar y dywediadau hyn sy'n cynnwys 'wrth'
| dweud y drefn wrth | to scold, to tell off |
| wrth droed | oar the bottom of, at the foot of |
| wrth ei bwysau | at a leisurely pace |
| wrth ei waith | at his work |
| wrth fodd | over the moon, in [one's] element, delighted |
| wrth gefn | in reserve, on hand |
| wrth gwrs | of course |
| wrth law | to hand, convenient |
| wrth natur | by nature |
| wrth [fy] hun[an] | by myself |
| wrth y llyw | at the helm |