When I was in high school I used to use the word “wallah” very casually and I wouldn’t imply it as an oath. I would say for example “wallah that’s not fair” or “wallah that test was impossible”. I have stopped doing this but I want to know if I should pay Kaffarah for breaking oaths for this? If so it’s impossible for me to remember how many times of done this so how much do I give?

There is no Kaffarah for that