Nouns That Need Determiners: Countable Singular Nouns
We’ll start with some facts about nouns. First, some nouns in English can’t stand alone. For example, you can’t just say, “Cat crossed the road.” You have to say something like “A cat,” “The cat,” “Squiggly’s cat,” “Every cat,” or maybe “No cat.” “A,” “the,” the possessive noun “Squiggly’s,” “every,” and “no” are all examples of what linguists call determiners, and in English, some nouns have to have determiners.
So exactly which nouns need them? Countable, singular nouns, such as “cat,” must have a determiner.
Nouns That Don't Need Determiners: Proper Nouns
Of course, if you’re writing about a cat named Cat, or someone named Catherine who’s called Cat for short, then “Cat crossed the road” works. This brings us to one kind of noun that doesn't have to have a determiner: the proper noun. Proper nouns usually don’t have determiners; for example, you wouldn’t say “a Squiggly” or “every Squiggly,” except in the unusual situation where there’s more than one person named Squiggly.
Nouns That Don't Need Determiners: Plural Nouns
Plurals can go without determiners, too. Although you can say “the cats,” you can also just say “cats,” if you don’t have any particular cats in mind.
Nouns That Don't Need Determiners: Mass Nouns
Mass nouns—also called uncountable nouns—don’t need a determiner, either. Take the uncountable noun “information”: Although you can say, “I need your information,” or “I need the information,” you can also just say “I need information,” if you don’t want to be specific.
Mass nouns usually allow any determiner, provided it’s not one that implies the noun is countable. So you can’t say something like “one information,” “two information,” or “many information.” In particular, you can’t say “an information,” because “a,” which is a form of the word “one,” implies that “information” is a countable noun.
Ref: By