All engines use oil depending on a number of factors. The piston ring to borewall interface is not a perfect seal. Normal will be based on - the actual frequency, amount, mileage, drive cycle, etc.
That being said, most people don't check their oil and there is a ~1 quart tolerance so if you were lower than the full mark it wouldn't be an absolute requirement to add oil...
Just an example. 10k mile per quart oil usage is good on a low mileage, healthy engine. Throughout the engine life this may errode to something like 5k per quart. Still totally acceptable... If you change oil every 5k miles you would be down 1/2 quart at 2500miles (halfway between changes) and a diligent owner may add oil to keep it closer to the full mark. This addition of oil would not be regarded as an issue whatsoever.
Now, if you are going below the low mark within the span of an oil change I would agree to that being abnormal.
I won't get into variances in usage through the PCV system, but that is another normal source of oil usage in a modern engine...