一言も (not a single word)

A fixed expression meaning 'not (even) a single word,' following the [counter]+も+negative pattern. 一言も話さない ('not say a word'), 一言も返さない ('not even reply once'). Uses も to emphasize 'not even one of the smallest unit.' Generalizes to other minimal-counter+も+negative constructions: 一日も, 一円も, 一度も. Parallel patterns: 一回も~ない (not even once), 一人も~ない (not a single person).