da is an irregular adjective. When using da in a superlative context, we use cystal.
Irregular Adjectives
Absolute |
Equative as … as |
Comparative e.g. better |
Superlative e.g. best |
da |
cystal |
gwell |
gorau |
drwg |
cynddrwg |
gwaeth |
gwaethaf |
mawr |
cymaint |
mwy |
mwyaf |
bach |
cyn lleied / mor fach |
llai |
lleiaf |
isel |
mor isel |
is |
isaf |
uchel |
cyfuwch / mor uchel |
uwch |
uchaf |