不是

不是	bù shì	no / is not / not
不是	bù shi	fault; blame
不	bù	no; not so / (bound form) not; un-
是	shì	to be (followed by substantives only) / correct; right; true / (respectful acknowledgement of a command) very well / (adverb for emphatic assertion)
是	shì	variant of 是