I have been reading Lyn Davies’s book ‘A is for Ox’ in which she talks about the history of the alphabet and how each of the twenty-six letters have developed since Egyptian hieroglyphics. It’s fascinating to see how each letter has changed beyond recognition. So if you’re interested in letters or fonts, I highly recommend it.
The two different ways of writing the lower-case letter ‘a’ come from fifteenth-century Italy and the split between Italic and Roman forms. The Italic version is what most of us write with (‘ɑ’), also known as the Latin ‘alpha’ or ‘script a’, probably because it is easier and quicker to write. This developed in the fifth century after medieval Irish and English writers began to change what was the Greek letter ‘tau’.
The other version (‘a’) is the Roman form and features more frequently with the added arc over the top. This is a harder shape to make by the hand.