A Determiner is a word or a group of words that introduces a noun. It is an important noun modifier that introduces and provides context to a noun. Determiners in English precede a noun or noun phrase and include articles, numerals, demonstrative pronouns, possessive pronouns and indefinite adjectives.
Articles are among the most common of the determiners. ‘A and an’ are the indefinite articles. ‘A’ is used before countable singular nouns beginning with a consonant sound. ‘An’ is used before words with a vowel sound. ‘The’ being the definite article expresses the specificity of a noun.
A student is reading the textbook.
Richard is an honest boy.
The client is waiting since morning.
“This, that, these and those” are demonstrative pronouns. It requires a frame of reference in which an individual can point out the entities referred to by a speaker or a writer.
For example: This painting is very beautiful.
I want that white dress for the party.
Our, my, their, one’s…. are words that express possession of a thing. They are used before singular and plural nouns.
For example: This is Maria and her brother Tom.
A quantifier is a word or phrase which is used before a noun to indicate the amount or quantity. 'Some', 'many', 'a lot of', most, enough and 'a few' are examples of quantifiers.
For example: All the members are requested to attend the meeting.
Numerals or Numbers are of two types: Cardinals (one, two, three, etc) and Ordinals (first, second, third, etc). Cardinal numbers are adjectives that indicate quantity and Ordinal numbers indicate rank or order.
‘Anybody’, ‘someone’, ‘anything’, ‘somebody’, ‘everyone’ etc. which refer to something that is not definite or specific or exact. Such words are called indefinite pronouns
For Example: None answered the call.