Hi. Is <u><i>to be</i></u> considered an auxiliary verb in progressive tenses or not?<br/><br/>What about passive sentences?<br/><br/><i>Ex. They were palying outside. </i><br/><br/><i>Ex. I was told the story. </i><br/><br/><i>Ex. He had been playing for ten hours. </i><br/><br/>Thanks