Nouns are words that name people, places, animals, things, ideas, or qualities. They are fundamental to forming sentences. Let's explore their different types:

1. Proper Nouns: These name specific people, places, or things. They always begin with a capital letter.
   Examples: India, Rahul, Taj Mahal, Monday, January
2. Common Nouns: These name general people, places, animals, or things. They do not refer to a specific one and are not capitalized unless they start a sentence.
   Examples: country, boy, building, day, month
3. Collective Nouns: These refer to a group of people, animals, or things as a single unit.
   Examples: team, flock, army, bundle, committee
4. Material Nouns: These refer to the raw materials or substances from which things are made. They are typically uncountable.
   Examples: gold, wood, water, cotton, iron
5. Abstract Nouns: These refer to ideas, qualities, states, or feelings that cannot be perceived by the five senses.
   Examples: happiness, bravery, freedom, knowledge, peace

Countable and Uncountable Nouns:
- Countable Nouns: Nouns that can be counted and have both singular and plural forms.
Examples: book (books), chair (chairs), apple (apples)

• Uncountable Nouns: Nouns that cannot be counted individually and usually do not have a plural form.
  Examples: water, information, advice, furniture (We use "some water," "a piece of information," etc.)

Nouns can function in different "cases" depending on their role in a sentence.
1. Nominative Case (Subjective Case): The noun acts as the subject of the verb, performing the action.
Example: The dog barked loudly. (The dog is performing the action of barking.)

1. Objective Case: The noun acts as the object of the verb or a preposition, receiving the action.
   Example: She fed the dog. (The dog is receiving the action of being fed.)
   Example: He went to the park with his friend. (Friend is the object of the preposition 'with'.)
2. Possessive Case: The noun shows ownership or possession, usually indicated by an apostrophe ('s) or just an apostrophe for plural nouns ending in 's'.
   Example: Ria's book is new.
   Example: The boys' school is nearby.

Pronouns are words used in place of nouns to avoid repetition. They must agree with the noun they replace in number, gender, and person.

Types of Pronouns:
1. Personal Pronouns: Refer to specific people or things and change form based on person, number, gender, and case.
- First Person (speaker): I, me, my, mine, we, us, our, ours
- Second Person (listener): you, your, yours
- Third Person (person/thing spoken about): he, him, his, she, her, hers, it, its, they, them, their, theirs
- Cases of Personal Pronouns:
- Nominative/Subjective: I, we, you, he, she, it, they (used as the subject of a verb)
- Example: He ran fast.
- Objective: me, us, you, him, her, it, them (used as the object of a verb or preposition)
- Example: She saw him.
- Possessive: my, mine, our, ours, your, yours, his, her, hers, its, their, theirs (show ownership)
- Example: That is my book. That book is mine.

1. Reflexive Pronouns: End in -self or -selves and refer back to the subject of the sentence. They indicate that the action is performed by the subject upon itself.
   Examples: myself, yourself, himself, herself, itself, ourselves, yourselves, themselves
   Example: She accidentally cut herself.
2. Emphatic Pronouns: Look identical to reflexive pronouns but are used to emphasize the noun or pronoun. They are not essential to the sentence's meaning.
   Example: He built the house himself. (Meaning: He built it without help.)
3. Demonstrative Pronouns: Point out specific nouns.
   Examples: this, that, these, those
   Example: This is my favourite colour. Those are beautiful flowers.
4. Indefinite Pronouns: Refer to an unspecified person or thing. They do not refer to a particular noun.
   Examples: everyone, someone, nobody, anything, all, few, many, several
   Example: Everyone agreed with the decision.
5. Interrogative Pronouns: Used to ask questions.
   Examples: who, whom, whose, which, what
   Example: Who is at the door?
6. Relative Pronouns: Connect a dependent clause to an independent clause, referring back to a noun or pronoun (the antecedent).
   Examples: who, whom, whose, which, that
   Example: This is the book that I borrowed.

Pronoun-Antecedent Agreement:
A pronoun must agree with its antecedent (the noun it replaces) in number (singular/plural) and gender (masculine/feminine/neuter).
- Incorrect: Every student submitted their assignment.
- Correct: Every student submitted his or her assignment. (Or, rephrase for plural: All students submitted their assignments.)