(用於if 現在時態或現在完成時態之後)要不; 不然I'll go if you're going -- if not I'd rather stay at home. 你去我就去, 否則我寧可待在家裡。If you've finished we can have a coffee -- if not, you'd better keep working. 你要是完事了, 咱們可以喝杯咖啡--不然的話, 你最好接著幹下去。
並非Not that it matters, but how did you spend so much money in such a short period of time? 我不是說有什麼關係, 但是, 這麼短的時間裡你是怎麼花掉這麼多錢的?She hasn't written to me yet -- not that she ever said she would. 她還沒給我來信--倒不是她說過要給我寫信。