When to read 一人 and 二人 as いちにん and ににん?


WWWJDIC lists いちにん and ににん as alternative readings of 一人 {ひとり} and 二人 {ふたり},
but I can't recall anywhere I heard those readings except when counting more
than 10 people for example 三十一人 {さんじゅういちにん}. Is that the only situation where
一人 and 二人 are read as いちにん and ににん, or are there any other situations?




Other than your example `三十一人`, I can think of `一人前`, `二人前`, `二人三脚`, `二人羽織`.
But by itself, I don't think they are read as 'いちにん' or 'ににん'.




Other than your example `三十一人`, I can think of `一人前`, `二人前`, `二人三脚`, `二人羽織`.
But by itself, I don't think they are read as 'いちにん' or 'ににん'.

