Nouns:
- Nouns are words that name people, places, things, or ideas.
- Examples of nouns include: dog, book, teacher, happiness.

Pronouns:
- Pronouns are words that replace nouns in a sentence.
- They are used to avoid repetition and make sentences less repetitive.
- Examples of pronouns include: he, she, it, they.

Conjunctions:
- Conjunctions are words that connect words, phrases, or clauses in a sentence.
- They are used to join different parts of a sentence and show how they are related.
- Examples of conjunctions include: and, but, or, because.

Tenses:
- Tenses are used to indicate the time of an action or state of being in a sentence.
- There are three main tenses: past, present, and future.
- The past tense is used to talk about a past action or state.
- The present tense is used to talk about a current action or state.
- The future tense is used to talk about a future action or state.

Examples:
Nouns:
- The dog chased the ball.
- The book is on the shelf.
- The teacher is very kind.
- Happiness is important for our well-being.

Pronouns:
- He is going to the store.
- She loves to sing.
- It is a beautiful day.
- They are my best friends.

Conjunctions:
- I like apples and oranges.
- He is tired, but he keeps working.
- Do you want tea or coffee?
- I am happy because I passed the test.

Tenses:
- I played soccer yesterday.
- She is reading a book right now.
- We will go to the park tomorrow.

By understanding and practicing the use of nouns, pronouns, conjunctions, and tenses, your grammar skills will become stronger. Remember to pay attention to the context and use the appropriate form of each element in your sentences.