Found myself writing cause instead of because but I'm wondering if this isn't just bad grammer or style thing. Because sounds so formal. Is cause frowned on?
I think it's fine if it's in dialogue, because people will frequently say that. However, I don't think it's otherwise correct in written form.
For dialogue, you might want to write it with an apostrophe ('cause) to avoid confusion with the word "cause." Otherwise, stick to "because" because that's the correct way of writing it.
As other's have said, it really needs an apostrophe, and it's colloquial so it's fine wherever colloquial is fine.
The short form of because is 'cause - with the apotrosphe. Pure and simple 'cause' without the apostrophe means "the cause of something", such as, I don't know, "the explosion was caused by the gas leak in the building." Whereas 'cause, that would be: A: Why are you eating so much? B: 'Cause I'm hungry! Hence the text-speak "cus", which is still the only text-speak I use on forums lol. But I would not use 'cause unless your story is written from 1st person or else it's in direct speech. Writing 'cause in proper prose would be.... eeeeeek, I dunno, horrible.
yes, it would only work well in dialog, not narrative... unless it's first person narrative and the character would speak and write that way...