Sentence:  Bob Carroll may not bear quite as close a physical resemblance to LaGuardia as Tom Bosley does , but I was amazed at the way he became more and more Fiorello as the evening progressed , until one had to catch one's self up and remember that this <WSD>was</WSD> n't really LaGuardia come back among us again . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)