just gather a little bit of the comforter's corner up and tie the string around it....enough to hold it tight.... or, if you have the urge, sew a loop of heavy cord into the corner and tie into that loop instead.... and yes, it is to hold the comforter in place...... gives you a good place to grab hold and shake to distribute the covers equally when making the bed, too....

So this may be a stupid question I'm only 15.. I recently bought a duvet and down comforter I see inside the diver there are two strings ties on each corner. Is that to keep the down comforter in place? How do I tie the strings to my down comforter! Thanks!