A copula used in western Japanese dialects equivalent to 'da' (is/am/are); often used by older speakers or in dialectal speech.
それは本当じゃ。
That's true.
昔の村では、この言い方が一般的じゃった。
In the old village, this way of speaking was common.
そうじゃ、忘れておった！
Oh right, I had forgotten!
A colloquial contraction used in expressions like 'ja nai?' to mean 'isn't it?' or to seek confirmation; informal.
今日、寒いじゃ？（＝寒いじゃない？）
It's cold today, isn't it?
もう帰るじゃ（＝もう帰るんじゃない？）
You're leaving already, aren't you?