Comparative/superlative for two syllable words

Comparative/superlative inflection rules should be added because two syllable words are tricky.
It is common to use more and most for two syllable words end with -ful / -less / -ing / -ed / -ous
(-ing words are okay but other words are not okay)
painful - more painful - most painful
restless - more restless - most restless
tired - more tired - most tired
famous - more famous - most famous