Answer
By using the Past Tense and words and phrases that talk about the past.
Explanation:
Nostalgia is a sentimentality for the past, usually for a period or place associated with happy memories.
The speaker creates a tone of nostalgia by using:
- The Past Tense - the entire poem tells about things that happened in the past, the things the author is reminiscing about. We can see that the Past Tense is also used with would as the Past Tense form of the modal verb will to talk about things that used to happen, but no longer do.
- Words and phrases that tell about things that happened in the past - then, in those days.
