I was trying to understand indefinite pronouns from this English Grammar Guide site.
Everything was going smoothly until I bumped into this paragraph.
In affirmative statements, indefinite pronouns with some are used to describe indefinite quantities, those with every are used to describe completeness, and those with no are used to describe absence. Often indefinite pronouns with no are used in affirmative statements with negative meanings, but these statements don't use not.
I didn't understand the bold part. Specifically, I couldn't grasp the concept behind "affirmative statement with negative meaning".
I am beginner with English grammar, so it would be great if you explain it with clear and simple examples.