Mae'r gair Mo yn tarddu o ‘ddim’ + ‘o’ – (ddi)m o. Byddwn ni'n defnyddio Mo i ffurfio negyddol berfau cryno, hyny yw, fel rheol, yn yr amser gorffennol, neu yn yr amser dyfodol, e.e.

gweld + fi – Gwelais i / Gwela i
I saw / I will see

Dim ond gyda'r canlynol y byddwn ni'n defnyddio 'Mo'

1) Gwrthrychau pendant, hynny yw, ‘the + something' – y bwyd, y cwestiwn, yr e-bost, e.e:
Bwytais i fara
I ate (some) bread

Fwytais i ddim bara
I didn’t eat (any) bread

Bwytais i’r bara
I ate the bread

Fwytais i (ddi)mo’r bara
I didn’t eat the bread (Yn llythrennol – I didn’t eat nothing of the bread)

Mo comes from ‘ddim’ + ‘o’ - (ddi)m o. It is used when forming the negative of short form verbs, i.e. usually the past or future tenses, e.g:
gweld + fi – Gwelais i / Gwela i
I saw / I will see

It is only used with the following:

1) Definite objects, i.e.‘the’ something - y bwyd, y cwestiwn, yr e-bost, e.g:
Bwytais i fara
I ate (some) bread

Fwytais i ddim bara
I didn’t eat (any) bread

Bwytais i’r bara
I ate the bread

Fwytais i (ddi)mo’r bara
I didn’t eat the bread ( Lit. - I didn’t eat nothing of the bread)

2) Rhagenwau personol ac enwau priod – fi, ti, fe, hi, ni, chi, nhw, Ffred, Siân, e.e.

Gwelais i ti
I saw you

Welais i (ddi)mohonot ti
I didn’t see you

Gwelais i Siân
I saw Siân

Welais i (ddi)mo Siân
I didn’t see Siân

* Bydd rhaid ychwanegu terfyniadau at fôn yr arddodiad 'o' (sef, 'ohon-') pan fyddwn ni'n defnyddio rhagenwau personol, e.e.

Welais i mohonot ti /o fe/i hi/och chi/yn nhw
I didn’t see you/him/her/you/them

Byddwn ni'n hegor ail ran y ffurfau fel 'mo/honot' ar lafar, e.e.

Welais i mohonot ti > Welais i mo ti/Welais i ddim o ti

2) Personal pronouns and names - fi, ti, fe, hi, ni, chi, nhw, Ffred, Siân, e.g.

Gwelais i ti
I saw you

Welais i (ddi)mohonot ti
I didn’t see you

Gwelais i Siân
I saw Siân

Welais i (ddi)mo Siân
I didn’t see Siân

*An ending has to be added to the root of ‘o’ - ‘ohon’ when the personal pronouns are used, e.g:

Welais i mohonot ti /o fe/i hi/och chi/yn nhw
I didn’t see you/him/her/you/them

The above are often omitted in informal speech, e.g:
Welais i mohonot ti > Welais i mo ti/Welais i ddim o ti

3) Rhagenwau meddiannol – fy, dy, ei, ein, eich, eu, e.e.

Gwelais i dy frawd di
I saw your brother

Welais i (ddi)mo dy frawd di
I didn’t see your brother

3) Possessive pronouns – fy, dy, ei, ein, eich, eu, e.g.

Gwelais i dy frawd di
I saw your brother

Welais i (ddi)mo dy frawd di
I didn’t see your brother

 


 

* Rhagor o Enghreifftiau / More Examples

 

1. Gwelon ni gath yn yr ardd ddoe, a gwelwn ni hi eto 'fory, siŵr o fod
We saw a cat in the garden yesterday, and we'll see it again tomorrow, probably

2. Prynodd hi gaws, ond brynodd hi ddim llaeth
She bought (some) cheese, but she didn't buy (any) milk

3. Prynwn ni'r dŵr, ond brynwn ni (ddi)m o'r gwin
> Prynwn ni'r dŵr, ond brynwn ni mo'r gwin
We'll buy the water, but we won't buy the wine

4. Bwytai hi'r brechdanau, ond fwytai hi (ddi)m o’r cyri malwod
> Bwytai hi'r brechdanau, ond fwytai hi mo’r cyri malwod
She would eat the sandwiches, but she wouldn't eat the snail curry

5. Gorffennon nhw'r bwyd, ond yfon nhw (ddi)m o'r siampên
> Gorffennon nhw'r bwyd, ond yfon nhw mo'r siampên
They finished the food, but they didn't drink the champagne

6. Gofynna i'r cwestiynau, ond dderbynia i (ddi)m o'r atebion, mwy na thebyg
> Gofynna i'r cwestiynau ond dderbynia i mo'r atebion, mwy na thebyg
I'll ask the questions, but I won't get the answers, more than likely

7. Darllenais i'r e-bost, ond 'sgrifennais i (ddi)m o'r llythyr
> Darllenais i'r e-bost, ond 'sgrifennais i mo'r llythyr
I read the e-mail, but I didn't write the letter

8. Palwn i'r ardd, ond olchwn i (ddi)m o'r llestri
> Palwn i'r ardd, ond olchwn i mo'r llestri
I would dig the garden, but I wouldn't wash the dishes

9. Gwelon ni fe, ond welon ni (ddi)m ohoni hi
> Gwelon ni fe, ond welon ni mohoni hi
> Gwelon ni fe, ond welon ni mo hi
We saw him, but we didn't see her

10. Pryniff hi gaws, ond bwytiff hi (ddi)m ohono fe
> Pryniff hi gaws, ond bwytiff hi mohono fe
> Pryniff hi gaws, ond bwytiff hi mo fe
She'll buy cheese, but she won't eat it

11. Clywon nhw Ffred ond glywon nhw (ddi)m o Sandra
> Clywon nhw Ffred ond glywon nhw mo Sandra
They heard Ffred, but they didn't hear Sandra

12. Prynen ni laeth ond yfen ni (ddi)m ohono fe
> Prynen ni laeth ond yfen ni mohono fe
> Prynen ni laeth ond yfen ni mo fe
We would buy milk, but we won't drink it

13. Gwaeddet ti arnon ni, ond helpet ti (ddi)m ohonon ni
> Gwaeddet ti arnon ni, ond helpet ti mohonon ni
> Gwaeddet ti arnon ni, ond helpet ti mo ni
You would shout at us, but you wouldn't help us

14. Gwelodd Ffred ein chwaer ni, ond welodd e (ddi)m o'n brawd ni
> Gwelodd Ffred ein chwaer ni, ond welodd e mo'n brawd ni
Ffred saw our sister, but he didn't see our brother

15. Clywodd y plant eich cath chi, ond chlywon nhw (ddi)m o'ch ci chi
> Clywodd y plant eich cath chi, ond chlywon nhw mo'ch ci chi
The children heard your cat, but they didn't hear your dog

16. Golchwn ni'u dillad nhw, ond olchwn ni (ddi)m o'u 'sgidiau nhw
> Golchwn ni'u dillad nhw, ond olchwn ni mo'u 'sgidiau nhw
We'll wash their clothes, but we won't wash their shoes

17. Gwyliais ei ferch e'n perfformio, ond wyliais i (ddi)m o'i fab e
> Gwyliais ei ferch e'n perfformio, ond wyliais i mo'i fab e
I watched his daughter performing, but I didn't watch his son

18. Glanhân nhw'i char hi, ond lanhân nhw (ddi)m o'i thŷ hi
> Glanhân nhw'i char hi, ond lanhân nhw mo'i thŷ hi
They'll clean her car, but they won't clean her house