Same, un, yr un

Sand, tywod

Save, eithr, ond: cadw, gwared

Scab, crachen, cramen

Scar, craith: creithio

Scum, ewyn: diewynu

Seal, morlo; sel: selio

Seam, gwrym, gwnïad

Sear, serio

Seat, eisteddfa; gosodiad