The letters U, V and Y were all taken from the letter "Upsilon," and it may have been derived from the queer Hebrew form of "Ayin" which closely resembles Y. The letters U and V were interchangeable. Upsilon, known as the "Samian letter," was used by Pythagoras as an emblem to represent the parting of the ways—the young man making a choice in life.
W
Our Anglo-Saxon forefathers contributed two letters, W (wen) and another often confused with Y, called "thorn." These were introduced during the thirteenth century. The French always called the former letter double vay, and in English it may be said to represent double U, as its name indicates. The letter "thorn" had the value of the digraph "th," and "ye" in old English should be pronounced "the" like the definite article.
X-Z
Although we have no direct need for the letter X, for Z can be substituted for it when it is used as an initial letter, and "ks" when used elsewhere, it has remained in the alphabet since its frequent use by the Greeks. It came from the Roman X (eex) which may have been derived from the Greek "ksi." The latter resembles the Phoenician character "samech," meaning a post or support.
The dagger "zayin" from which we obtain our Z must have been important in the daily lives of the Greeks, Hebrews and Phoenicians for it occupies the sixth place (Zeta) and the seventh in the latter alphabets. The Romans did not change its name or shape, but although there has been little change in 2,000 years we see little resemblance to the short sword in the letter the Romans gave to us.
Many slight changes that have occurred in the formation of the letters of the alphabet may be accounted for. At first the Greeks wrote from left to right in one line and from right to left on the next line—a mode of writing which has been termed "boustrophedon" because it runs as an ox plow does in a field, up one furrow and down another. It is due to this fact that many letters were reversed from their original prototypes. It is interesting to note that recently books for the blind have been embossed in this manner.
The small letters of the alphabet, sometimes called "lower case" letters because printers keep them in a case below the capitals, or "minuscule letters" in contrast with "majuscule," or capital letters, illustrate further changes due to rapid writing of capitals in a cursive or running hand.
The few characters selected by the Phoenicians, the great traders, artificers and farmers of the ancient world, not only influenced Greek literature and life, Roman and modern nations in Europe, but also spread eastward to the very walls of China. The Hebrews copied them as a whole and retained the original names with only slight variations. They did change the shapes because a different writing instrument was employed.