Sentence:  Each time Letch `` went up '' in his `` lines '' , I was the one to <WSD>be</WSD> patient , helpful and apologetic while he indulged in outbursts of temperament , profanity and abuse , blaming others , going into `` sulks '' and , on more occasions than I care to count , storming off the `` set '' for the rest of the day . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)