5. Almost every word has an accent, but very seldom has more than one;
and, when this happens, it is an acute thrown back upon the last syllable
from one of those words called enclitics (_leaning back_), which in that
case has none, unless it be followed by another enclitic. In no other
case than this can a last syllable have an acute accent, except before a
full-point, colon, or note of interrogation, when the grave accent of the
last syllable is changed to an acute,—a circumstance which has often led
printers, who were ignorant of the reasons for accenting the same word
differently in different situations, to think that there was an error in
their copy, and thus to make one in their proof. Most errors, however,
proceed from those who do not think at all about the matter.