[Grammar] commoner/ more common, narrower/more narrow

[why_me]

Hello,

I seek explanation as to why both forms are correct; commoner/ more common, narrower/more narrow.

Thank you.

 

[Rover_KE]

Welcome to the forums.:-D

We're more used to being asked why things are wrong rather than why they are right.

'Common' and 'narrow' are just two of the many two-syllable adjectives with two forms of the comparative and superlative.