Here are some guidelines for when NOT to use the definite article 'the'. I hope it's helpful :)
1. When you talk about things in general:
*The main rule to remember is: you don’t need an article when you talk about things in general.
For example:
Cats are very cute-correct
The cats are very cute -incorrect because this is about cats in general, not a specific cat.
2. Names – holidays (such as Christmas, Valentine's Day, New Year and Eid al-Fitr) geography (For example:countries, states, cities, towns, continents, single lakes, single mountains), companies (For example: Mircosoft, Mc Donalds & Facebook) languages (For example: Arabic, English, French) and Universities (For example: Oxford, Harvard).
For example:
I live in South Africa - correct
I live in the South Africa -incorrect
Microsoft is a very big company-correct
The Microsoft is a very big company - incorrect.
3. Streets, some locations and places do not need an article.
For example:
I live on 26 Main Street - correct
I live on 26 the main street - incorrect.
4. Sports.
ports and other physical activities do not need an article.
For example:
I love to do yoga - correct.
I love to do the yoga - incorrect.
5. Acronyms
An acronym is an abbreviation (a short form) of a name. It uses the first letter of each word to form a new word.
a) If the acronym is pronounced as a word (not individual letters), don’t use ‘the.’
For example:
SCUBA (short for: self-contained underwater breathing apparatus).
I like SCUBA diving - correct.
I like the SCUBA diving - incorrect.
b) The is not used before university acronyms:
For example:
I have a MBA degree. - correct.
I have the MBA degree -incorrect.