When "the" is usually used:
* Formal titles: "The United States," "The United Kingdom," "The Hague." These names are considered collective entities.
* Groups of people: "The Smiths," "The Beatles" (referring to the band as a whole).
* Geographical features: "The Amazon River," "The Great Barrier Reef," "The Grand Canyon."
* Named buildings or institutions: "The White House," "The Louvre Museum," "The University of Oxford."
When "the" is usually *not* used:
* Names of specific people, places, or things: "John Smith," "London," "Mount Everest." These are generally considered unique and don't need a definite article.
* Most countries (but not all): "France," "Brazil," "Japan." However, some exceptions include "the Netherlands," "the Dominican Republic," and "the United States."
* Days of the week, months, holidays: "Monday," "December," "Christmas."
* Languages: "English," "Spanish," "Mandarin."
It's not always clear-cut:
* Some names can be used with or without "the," depending on context: "The Red Sea" vs. "Red Sea."
* Some names are more naturally associated with "the" even though they're proper nouns: "The World Health Organization," "The International Monetary Fund."
Key Takeaway:
The use of "the" depends on the specific proper noun and how it's being used. Think about whether the noun refers to a unique entity, a collective group, or a specific place. If you're unsure, err on the side of omitting "the" unless it's clearly the standard usage.
If you have a specific example in mind, feel free to share it, and I can help you determine whether "the" is necessary!