| Dw i'n meddwl bod ... | I think that ... |
| Dw i'n credu bod ... | I believe that ... |
| Dw i'n siw^r bod ... | I'm sure that ... |
| Dw i'n sicr bod ... | I'm certain that ... |
| Dw i'n gwybod bod ... | I know that ...
|
Dw i'n meddwl bod bwyta'n iach yn bwysig. | I think that eating healthily is important. |
Dw i ddim yn credu bod bwyta'n iach yn anodd. | I don't think that eating healthily is difficult. |
Dw i'n siw^r bod y plant yn heini. | I'm sure that the children are fit. |
Dw i'n gwybod bod Shane Williams yn gyflym. | I know that Shane Williams is fast. |
Dw i'n sicr bod sglodion yn llawn braster. | I'm certain that chips are full of fat. |
Dw i'n meddwl bod salad yn iachus. | I think that salad is healthy. |