Soft: Noom and Nim and other confusing word pairs

[digbeth]

นุ่ม and นิ่่ม....

after much exposure... you can just about get by on which adjective word is appropriate for which subject

you wouldn't say a chair is nim... เก้าอี้ นิ่ม but เก้าอี้นุ่ม sounds okay, cushion เบาะนิ่ม is also okay

Are there a substitute in English that holds true... soft vs flaccid maybe?

has anyone found a rule for this pair of adjectives? or is it always irregular and you'd have to memorize them all?

What about other confusing word pairs?

Hurt: Jeb and Puad เจ็บ ปวด I feel ปวด is more of an ache 'inside' like if you have a cut, it is เจ็บ but after a few days and it throbs that's ปวด

ปวดหัว is headache but if you say เจ็บหัว that sounds like something hit you in the head