It's usally negative, but it doesn't have to be always.
Heard in a coffee bar:
"These days you don't never get nuthing for nuthing."
Damn right, too!
You ain't wrong there. ;-)
"Two negatives can be negative or positive, but two positives can never be negative.'
(-) * (-) = +
(-) * (-) = dramatically error
Shakespeare used them with a negative meaning.
'This project ain't going nowhere.'
'You're wrong- it isn't going nowhere.'
The first is negative, the second positive.
Joan, Shakespeare died 400 years ago; things have moved on.
It's a negative, however the speaker rarely intends for it to be. "This project ain't going nowhere" means this project is going somewhere. The speaker means the opposite.
I don't agree, Mr Trilby. The first speaker means that the project isn't going anywhere. It's the second speaker who disagrees