A or mi can both occur as 1SG subject pronouns, but only mi occurs as independent pronoun (in elliptical or emphatic answers).
I and im can occur as 3SG subject pronouns, but only im occurs as independent pronoun.
Dey and dem can occur as 3PL subject pronouns, but only dem occurs as independent pronoun.
Source: Escure 1985
Source: Escure 1980-1989