たりとも

たりとも is a formal, emphatic expression meaning "not even" or "not a single". It is used to stress that absolutely none of something is acceptable, possible, or allowed – not even the smallest amount. It always appears with a negative predicate and is typically preceded by a minimal quantity expression such as いちびょう一秒 (one second), ひとり一人 (one person), いちえん一円 (one yen), いっぽ一歩 (one step), いっしゅん一瞬 (one instant), etc.

Structure

The basic pattern is:

Number/Counter (typically 一～) + たりとも + Negative predicate

The expression strongly emphasizes zero tolerance – the speaker is asserting that not even the absolute minimum quantity is permitted or present. Because of this emphatic quality, it is most commonly found in written language, formal speech, commands, and strong declarations.

Nuance

Compared to softer expressions like 〜～も (e.g. 一秒も無駄にしたくない), たりとも carries a much stronger, more resolute tone. It conveys firm determination or strict prohibition, making it suitable for dramatic, literary, or authoritative contexts.

Common collocations

たりとも frequently appears with expressions like:

• ひとつ一つたりとも – not even one (thing)
• いちにち一日たりとも – not even one day
• いっしゅん一瞬たりとも – not even an instant
• いってき一滴たりとも – not even a single drop