... y gallwch greu I' w- Wneudau hierarchaidd gan glicio efo botwm dde' r lygoden ar I' w- Wneud sy' n bodoli a dewis Is- I' w- Wneud Newydd oddiar y ddewislen cyd- destun?
... that you can create hierarchical to-dos by clicking with the right mouse button on an existing to-do and selecting New Sub-to-do from the context menu?