Difference Between Ache and Pain

Ever wondered if there is any difference between ache and pain! Yes there is.

Head and ache are collocations (word partnerships) that always go together. You have to accept the practices of people of a specific language . In a way it is like a human partnership.
In addition "an ache" is a continuous dull pain whereas "a pain" can be either continuous or sudden.

Head/tooth/stomach/back ache.
Toothache/headache/backache
Stomach ache
Ache is both a verb and a noun: My back aches / I have got a backache.
Heart ache is figurative to mean worries
In written English you can use "ache for" to mean "a strong desire, long for":
I was aching for home / He ached to see her.


Pain is only a noun.

“Pain” can also collocate with “pleasure” to form compound nouns (bi-nominals). Pain can be: dull /sharp /stabbing. People can “double up in pain”. Pains (in plural) can also mean effort: go to (take) great pains (be at pains) to help them. Some people are a pain in the neck (get on your nerves).

Pain can be used both as a countable or as an uncountable noun because it can be physical (body) or mental (emotional).

Another word used as an adjective is "sore" : I have got a sore wrist or a sore throat.

Some more examples:
I have got a pain in my chest.
I have got sore feet from jogging.

Ironically "ache" and "pain" can collocate as in: aches and pains.