I don't understand well about the rules of Subject and Verb Agreement with Plural Proper Nouns. I found these sentences from the internet.
The West Indies is a large group of islands that separate the Caribbean Sea from the Atlantic Ocean.
The Rocky Mountains are notable for containing the highest peaks in central North America.
When can I use singular or plural verb with Plural Proper Nouns?Could you explain it to me? Thank you very much!
Plus, Plural last names,like the Johnsons and the Smiths and so on,have to take singular or plaral verbs? Can you provide some examples?