once
例子
The bus comes once an hour.
公交车每小时来一次。
1.1
一次, 哪怕一次
on even one time, if ever
例子
Did she once consider my feelings?
她曾考虑过我的感受吗？
例子
She once lived in New York before moving here.
她曾经住在纽约，然后搬到了这里。
03
一次, 曾经
used to indicate one generation of separation in family trees
例子
She 's my aunt once removed, my grandmother's sister.
她是我的表姑妈，我祖母的妹妹。
once
01
一旦, 一...就...
used to express that something happens at the same time or right after another thing
例子
Once the concert ends, we'll go backstage to meet the band.
一旦音乐会结束，我们将去后台见乐队。
Once
01
一次, 仅此一次
a single occurrence
例子
Once is enough, do n't ask again.
一次就够了，别再问了。
