Final answer:
The phrases that suggest the narrator's sentimental tone are 'Seeing clearly that an era of my life was ended' and 'my sweet-voiced nursery-school tot replaced by a long-trousered, swaggering character who forgot to stop at the corner and wave good-bye to me.'
Step-by-step explanation:
The phrases that suggest the narrator's sentimental tone are 'Seeing clearly that an era of my life was ended' and 'my sweet-voiced nursery-school tot replaced by a long-trousered, swaggering character who forgot to stop at the corner and wave good-bye to me.' These phrases indicate a sense of nostalgia and sadness as the narrator reflects on the changes in their child and the passing of time.