1.
both; all (of them)
Attaches to a quantity word to mean 'every one' of the group counted, including both or all members without exception. The set must already be specified in context.
Attaches directly to a counting expression to mean 'every one of that number'. The group must already be identified in context, and the speaker is asserting that the predicate holds for each member without exception.
Common patterns
- 二人とも: both people
- 二つとも: both things
- 三人とも: all three people
- 両方とも: both (of two options)
- 全員とも (less common; usually just 全員)
Watch out
With a negative predicate the meaning is "none of them", not "not all of them": 二人とも来なかった means neither of them came.