Few--or a Few?

Recently, on its Lingua Franca blog, the Chronicle of Higher Education reported on the failure of the publisher Elsevier to provide responsible copy editing to two Russian and French coauthors.

One inaccuracy that the publisher failed to correct was the use of a few when the authors (whose native languages are not English) should have used few. What's the difference?

As the author of the blog post, Geoffrey Pullum, explains, both mean a small number. But here's the difference. Few suggests a quantity of something so small that there might as well be none. A few suggests a quantity that, although small, is nevertheless large enough to matter.

There are few dangers to worry about means that what you are about to do is pretty safe. There are a few dangers to worry about means that you should be on guard--chances are, nothing will happen, but you should be on the lookout, just in case.