Examples
méi yǒu没有bēi guān悲观zhǔ yì主义zhě者jiù就méi yǒu没有lè guān乐观zhǔ yì主义zhě者。
没有悲观主义者就没有乐观主义者。
If there were no pessimists, neither would there be any optimists.
我时而乐观，时而悲观。
I am by turns an optimist and a pessimist.
每个人都感到悲观。
Everyone feels pessimistic.