Simple, Old-Fashioned
"Dolls" are "poppets" and contractions (like "don't) are non-existent... but dropped g's are everywhere. What's going on? Well, Miller is trying to write in the simple language of Puritan country folks, while at the same time employing old-fashioned vocabulary and grammar.
Have a look-see:
ABIGAIL: She heard you singin' and suddenly she's up and screamin'.
MRS. PUTNAM: The psalm! The psalm! She cannot bear to hear the Lord's name!
PARRIS: No, God forbid. Mercy, run to the doctor! Tell him what’s happened here! Mercy Lewis rushes out.
MRS. PUTNAM: Mark it for a sign, mark it!
Rebecca Nurse, seventy-two, enters. She is white-haired, leaning upon her walking-stick.
PUTNAM, pointing at the whimpering Betty: That is a notorious sign of witchcraft afoot, Goody Nurse, a prodigious sign!
MRS. PUTNAM: My mother told me that! When they cannot bear to hear the name of—
PARRIS, trembling: Rebecca, Rebecca, go to her, we're lost. She suddenly cannot bear to hear the Lord's name! (I.213-220)
You can also see that the narrative asides are slightly more complex and use standard 1950s language.