Answer: A typical twin size mattress is 38" x 75" so a twin comforter will be larger than this by several inches in both length and width. There is variety with different manufacturers, etc. But this is the minimum that a comforter could be to fit on the mattressComforter sizes vary slightly from manufacturer to manufacturer, but generally they are about:Twin 68"x 86" to 92" long Full 80"x 90"Full/Queen 88"x 88" Queen 86"x 94" King 110"x 96"Twin and Full sizes in particular vary considerably in length and slightly in width. This may be to accommodate twin XL mattresses or just taller teens and adults in full size beds, or to cut costs on a cheaper blankets.
Answer: There is no such thing as queen sized pillow cases, all pillows are usually the same size unless you have one of those long pillows that go across the bed. But if you are buying a pillow case, there are no sizes.