Elizabeth hit him across the head playfully with the tea towel.
"Ah, sure 'tis years before my time, son."
"Sure 'tis true," said Jack."
No, you t'aren't at all," joined in Holly.
They both stopped and started at her. "Since when is there such a word as t'aren't?" laughed her mum.
請教 'tis 、t'aren't 是什麼的縮寫？