In Present tenses^x, Auxiliaries^x, Present progressive^x

When he returns to Manhattan 1000 years later it has been destroyed and rebuilt three times 2 What

Yes; further to Pieanne's and Roro's comments, in sentence #2, 'am' acts as an auxiliary verb. We use the appropriate present tense of the verb 'to be' + the present participle to form the present progressive tense: 'I am / going to the store.' 'He is / going to the store.' etc. This denotes...