"Yeth."
"And ain't I older than you?"
"Courth."
"And wasn't I born afore you?"
"Yeth, Ikey."
"Then 'ow can your birfday come afore mine?"
"'Cos it doth."
"Stoopid!"
"It doth, arx Esty," Sarah would insist.
"Than't teep in my new bed," Ikey would threaten.