Sweeting cider after fermenting 7 Days?

How can I sweeten cider after it has been fermenting for 7 days?
Can I add sweetener now and let it continue to ferment?
Should I sweeten after fermentation has stopped?

I have 2-1 gallon jugs of apple juice. I have used ale yeast. I have added nothing else so far.

If you add a fermentable sweetener, it will ferment out if you do nothing.

You have a few options depending on if you want it flat or carbonated.

1. Use a non-fermentable sweetener, then you can do whatever you want.

2. Use a fermentable sweetener, and allow it to carb (or not), then pasteurize.

3. Use chemicals to stop the yeast (I've never done this myself, but there are plenty of people here who will tell you how to do it) and sweeten and bottle it flat.

Of course if you're kegging there are other options.