1. "Citizen'' should be in its plural form, Citizens
2. "Motivations" should be in the singular form.
3. "Metal worker" should be in the plural form, "metal workers," because there is a comparison between Yellin and all the other metalworkers in America.
4. "Children" is the plural form. An "s" should not be added
5. The use of the plural verb "learn" and the pronoun 'their" indicates that the noun "calf" should be in plural form, calves
6. "Advice" does not have a plural form.