As per the article rule, we should not use an indefinite article before the non countable nouns. But following are the examples of the indefinite articles with non countable nouns.

  1. Day 3 has been a success.
  2. it's been a great journey.
  3. it's a hell lot of stuff.
  4. what a wonderful tour.

Could anyone please explain, why are we using 'a' in the above sentences?

  • 3
    None of these are non countable. – Daniel Roseman Apr 18 at 11:30
  • It's strange that you consider all the examples as countable. – rahul soni Apr 18 at 11:38
  • 3
    Many, perhaps most uncountable nouns can also be used as countable nouns (usually with a slight difference of meaning). "Success" is often uncountable but also often countable (as here). "Journey" and "tour" are always or almost always countable, anyway, though. – rjpond Apr 18 at 11:40
  • What about this one- it's been a great pleasure. – rahul soni Apr 18 at 11:52
  • 1
    Again, "pleasure" is sometimes countable, sometimes uncountable. That is why Cambridge marks it "[C or U]". dictionary.cambridge.org/dictionary/english/pleasure . It's also why Lexico says "mass noun" for the main entry but "count noun" for one of the subsenses. lexico.com/definition/pleasure – rjpond Apr 18 at 12:05

Many nouns can be used as both countable and non-countable. In three of the examples you give there are nouns that are nouns that are completely normal as countable nouns: "a success", "a journey", and "a tour". In the case of journey and tour they most often used as countable nouns, with regular plurals. In fact I can't think of a natural expression in which they are clearly non-count nouns.

The word "success" can be both count and non-count.

Success was easy for him (non count) / Day 3 was a success (count)

"A success" means "A successful event or time period"

Example number 3 is slightly different. It uses the phrase "a lot of..." ("hell" is merely emphatic and it should perhaps be "a hell of a lot of stuff") here is is actually the noun "lot" that is countable. But this is now an idiom, and works with both plural count nouns, and non-count nouns

A lot of peas / A lot of rice.

Similarly "a hell of something" is also idiomatic, and in this idiom "hell" is a countable noun.

From the comments "A great pleasure" is like "a success", except that the count form of pleasure is less common, and mostly used in this kind of conversational expression. However you can say "A good night's sleep is one of life's pleasures." (from wiktionary)

Not the answer you're looking for? Browse other questions tagged or ask your own question.