A reflexive pronoun is unchangeable, whereas a strengthening pronoun has case forms.

A reflexive pronoun must always be placed immediately after the verb, while a strengthening pronoun is placed at the end of the sentence.

The reflexive pronoun correlates with a personal pronoun, while the strengthening pronoun correlates with a possessive pronoun.

The reflexive pronoun is used in connection with the verb (as an object), while the strengthening pronoun is used in combination with the noun or pronoun (for emphasis).