Relative pronouns can be either a subject or an object in relative clauses. When a relative pronoun is a subject, it is followed by a verb. When it is an object, it is followed by a noun or a pronoun.
Example: Subject
Do you know the man who talked to me?
The peaches that are lying on the table are tasty.
We will stay at a hotel which is next to the beach.
That is the film which is very exciting.
Object
Do you know the man who I talked to?
The peaches that you bought in the shop are tasty.
We will stay at a hotel which my friend has recommended to us.
That is the film which I like very much.
Exercise 1.
Subject Pronouns or Object Pronouns?
Decide whether the relative pronoun is a subject pronoun or an object pronoun.
1. Do you know the girl who I danced with?
2. Do you know the girl who danced with me?
3. The apples that are lying on the table are bad.
4. The apples that we bought in the shop are bad.
5. We will stay at a hotel which is not far from the beach.
6. We will stay at a hotel which my friend has recommended to us.
7. That is a museum which I like very much.
8. That is a museum which lies in the heart of the town.
9. This is the man who Barbara visited in Scotland.
10. This is the man who lives in Scotland.
Omission of the relative pronoun
A relative pronoun introduces a relative clause. But there are some cases when you can omit a relative pronoun.
Omission of the relative pronoun is possible if a pronoun functions as the object of a main clause.
Example:
Do you know the girl who he is talking to? Or Do you know the girl he is talking to?
The film which / that I saw two days ago was very interesting. or
The film I saw two days ago was very interesting.
I didn’t like the book which / that you gave me. or
I didn’t like the book you gave me.
Where is the pencil which / that I lent you? Or
Where is the pencil I lent you?
Exercise:
2. Write relative clauses without using the relative pronoun.
1. I gave you a book. It had many pictures.
→ The book I gave you had many pictures.
2. I am reading a book at the moment. It is very interesting.
→ The book 
3. You live in a town. The town is very old.
→ The town
4. The sweets are delicious. I bought them yesterday.
→ The sweets
5. The football match was very exciting. My friend played in it.
→ The football match
6. The letter hasn't arrived yet. I posted it three days ago.
→ The letter
7. He lives in a house. The house is not very big.
→ The house
8. They are playing a song on the radio. Do you like it?
→ Do you like
9. Jane wore a beautiful shirt yesterday. Did you see it?
→ Did you see
10. Sue is going out with a boy. I don't like him.
→ I don't like
Conjunction: Definition and Examples
The conjunction is the part of speech used as a “joiner” for words, phrases, or clauses in a particular sentence. It links these words or groups of words together and the thoughts that different parts of the sentence convey will be connected.
In the English language, conjunctions come in three basic types: the coordinating conjunctions, the subordinating conjunctions, and the correlative conjunctions.