If a verb finishes with a vowel ( a,e,i,o,u,w,y), get rid of the vowel and add on es i or ais i! Cysgu Cysges i Do you see?
Y ferf Y gorffennol Saesneg cysgu Cysgais i or cysges i I slept Deffro Codi Ymolchi Gwisgo Bwyta Gwylio Teimlo Teithio Siopa Prynu Gwario chwarae
If a verb finishes with a consonant then just add on es i or ais i! Siarad Siarades i Do you see?
But A very big But! If a verb finishes with ed or eg get rid of both letters and add on es i or ais i. cerdded cerddes I Do you see?
Y ferf Y gorffennol Saesneg eistedd eisteddais I sat Edrych Dewis Symud Siarad Yfed Rhedeg clywed