Question

Rivers → article is used article is not used names of countries in the plural → article is used article is not used continents → article is used article is not used streets → article is used article is not used relatives → article is used article is not used musical instruments → article is used article is not used towns → article is used article is not used mountain ranges → article is used article is not used names of countries in the singular → article is used article is not used family names in the plural → article is used article is not used

Answer 1

1) rivers - да (the Nile, the Danube)
2) да - НЕКОТОРЫЕ архипелаги и объединения стран (the Canary Islands, the Philippines, the United States)
3) continents - нет
4) streets - нет
5) relatives - нет (если имеются в виду родственники)
6) musical instruments - да и нет, в зависимости от случая и контекста (Where is my guitar? / Miss Anna plays on the piano every Saturday);
7) towns - нет ;
8) mountain chains - да (the Andes, the Rockies);
9) countries in singular- нет (кроме the Netherlands, the Dominican Republic и любой другой республики);
8) family names in plural - да (The Tolstoys often come to visit us.);

Answer 2

It seems like you're looking for a pattern or rule regarding the usage of articles (like "the" or "a/an") with different types of nouns. Here's a breakdown based on the examples you've provided:

Article "The" is used:

• Rivers (e.g., "the Nile," "the Amazon")
• Continents (e.g., "the Americas," "the Europe")
• Mountain ranges (e.g., "the Himalayas," "the Rockies")

Article "A/An" is used:

• Musical instruments (e.g., "a guitar," "an accordion")

No article is used:

• Names of countries in the plural (e.g., "Japan," "France")
• Streets (e.g., "Main Street," "Broadway")
• Relatives (e.g., "uncle," "cousin")
• Towns (e.g., "Paris," "London")
• Names of countries in the singular (e.g., "Italy," "Canada")
• Family names in the plural (e.g., "the Smiths," "the Johnsons")

It's important to note that English articles can be complex and are not always governed by strict rules. The usage of articles often depends on context, idiomatic expressions, and specific linguistic conventions. The above rules provide a general guideline, but there can be exceptions and variations in certain cases.