The Romans had a good sense of sentence structure but did not give the reader much help with punctuation between clauses or even between sentences. This must have given the Roman reader no end of trouble, what with the flexible word order of Latin and the mistakes which even the best of copyists could make from time to time.

Even in English, the absence of commas can be crucial to the understanding of a sentence. Take this old school rhyme:

Caesar entered on his head

A helmet on each foot

A sandal in his hand he had

- His trusty sword to boot.

"Punctuation" comes from the Latin punctum, which originally meant a dot or point made in a wax tablet but eventually became the full stop.

Other punctuation marks started as abbreviations of Latin words:

e.g. quaestio ("question") was shortened to Q. which became ?

io ("hurray") to I. and later to!

The Romans used a lot of abbreviations and shorthand. Tiro, Cicero’s secretary is said to have invented the symbol & (= et) which is now printed as & (= "and"). Years ago alphabets in schoolbooks included & after the letter Z and to show that is was not part of the alphabet itself, it appeared after the Z as "and per se &" (per se means "by itself"). So the name for the symbol & is ampersand.