The ampersand (&) was once treated as the 27th letter of the English alphabet: schoolchildren recited it right after Z. It was never a real letter, though, because it stands for a whole word, and, not for a sound, and when the habit of reciting it faded, it dropped out of the alphabet.
Everybody knows that the English alphabet has 26 letters. Fewer people know that there was a time when children learned 27. This article explains what the 27th character was, where it came from, and why it is no longer part of the alphabet.
The 27th character
The character that was dropped from the alphabet is the ampersand. Today you mostly see it in company names, and it is still very popular there. The sign itself is very old: it goes back almost 2,000 years, to the Romans.
In the early 1800s, schoolbooks often listed the & after Z, so children who recited the alphabet included it at the end. Ending the alphabet with "X, Y, Z, and" sounded odd, though, so they said "and per se and", which means "and, by itself, and". The Latin per se means "by itself", and it marked a sign that is also a word on its own. Spoken quickly, "and per se and" turned into ampersand, and that is how the sign got its name.
The & was not the only character treated this way. Three letters are also words on their own: A, I, and O. When children recited the alphabet, they said "A per se A", "I per se I", and "O per se O".
How the ampersand was created
The ampersand comes from the Romans. Roman scribes sometimes joined the letters E and t into one sign when they wrote the Latin word et, which means "and". Over the centuries, this joined form of et kept changing shape until it became the & you know today. In some fonts, especially in italics, you can still see the E and the t in it.
Because the & stands for a word and not for a sound, it was never a letter in the strict sense. As schoolbooks stopped listing it at the end of the alphabet, children stopped reciting it, and the alphabet went back to 26 letters.
The ampersand today
The ampersand is no longer part of the alphabet, but it is still widely used: in company names, in short forms such as R&D and Q&A, and in headings and titles where space is short. In ordinary sentences, write out and instead.
If you like the stories behind words, read how to get your made-up word into the dictionary or how people began to use punctuation in English. Numbers and symbols have rules of their own, too: see all you need to know about writing dates and times.