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How do you use 未 as a negator?

It means no.for example.我并未去过北京.I have't been to Beijing.这4根柱子实际上并未与天花板接触.This four pillars are not come into contact with ceiling.我的英语不好，句子可能有误，谢谢

“未”一般不单独使用，这里“并未”=“没有”，一边表示预期的计划没有执行，或与之前的猜测相反时使用。
1） 这次会议并未如期举行。
2） 其实他并未通过这次考核。

Commonly we use"未“in two different ways.
1.Objective facts
①.indicate things that didn't happen before(but not negate the possibility of future occurrence).
ex:I've never gone abroad.我从未出国。
②.An objective negation to a possibility(not include potential possibility)of some things or situations' existence.
ex:Actually those 4 posts do not contact with the ceiling.这4根柱子实际上并未与天花板接触。
Bacically we use that word as statements of some objective facts.
2.Subjective denials
When the subject is a person or some persons,we often use"未"to express the one's subjective denials or retorts.
ex:I never stopped waiting.我从未放弃等待。
You never disappointed me.你从未让我失望。
I've never thought about it that way before!我从未这样想过！