How did the use of "could of" and "should of" originate, and is it considered correct? [duplicate]

Solution 1:

The Oxford English Dictionary describes the etymology as:

Variant of have arising through misapprehension of the verb (when occurring as a clitic) as showing of.

It is described as being nonstandard and the definition is given as:

= have verb, used in the infinitive as the auxiliary of the perfect tense (especially in conjunction with modal verbs). Frequently in representations of non-standard speech.

The earliest recorded use is dated 1814, and it appears in a letter written in 1853 by the British novelist Charlotte Brontë.

Solution 2:

I think people write could of instead could've because it sounds like could of - it is a contraction of could have that is spelled could've but sounds the same as could of. The way it would be written without the contraction is I could have been hurt.

The phrase could of seems completely incorrect to me, as I can't even understand what it would mean.