Sentence:  She fell asleep leaning on her hand , hearing the house creaking as though it <WSD>were</WSD> a living a private life of its own these two hundred years , hearing the birds rustling in their cages and the occasional whirring of wings as one of them landed on the table and walked across the newspaper to perch in the crook of her arm . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)