What is the difference between a valid deductive argument and a fallacy?

Asap that time of year thou mayst in me behold when yellow leaves, or none, or few do hang upon those boughs which shake against the cold, bare ruined choirs, where late the sweet birds sang. in this excerpt, what is the best meaning for the word "late"? not on time until recently dead well into the evening

Read the excerpt from it's our world, too! : young people who are making a difference.the author’s purpose in this excerpt is to

Brendan is playing in the backyard.