Relative pronoun

Relative pronoun
Qui replaces the subjectin the dependent clause.
Je lis le livre. Le livre est sur la table.
        (1)         (2)

Le livre is the common noun in both the sentences.
Le livre (1) is the object in the first sentence.

Le livre(2) is the subject in the second sentence. 
Le livre(2) in the second sentence is already mentioned 
in the first sentence. So le livre (1) is called antecedent 
(already mentioned).

When the subject/objectin the first sentence (Principle clause)becomes the subject in the second sentence (dependent clause)remove the subject in the second sentence and use
the relative pronoun qui to join both the sentences.

Remember that the relative pronoun qui must be placed immediately after the antecedent and the relative pronoun qui must be followed by a conjugated verb.

Word order = ……… antecedent + qui + conjugated verb ………
           Je lis le livre    qui    est   sur la table.  
               …… le livre +  qui +  est 

Le garçon est mon ami. Le garçon lit le livre.
Le garçon qui lit le livre est mon ami.

Que replaces the directobject .

Que is the relative pronoun which acts as the direct object 
of the verb. 
Je lis le livre. J’achète le livre.
        (1)                (2)
Le livre is the common noun in both the sentences.
Le livre (1) is the object in the first sentence.
Le livre (2) is the object in the second sentence. 
Le livre (2) in the second sentence is already mentioned 
in the first sentence. So le livre (1) is called antecedent 
(already mentioned).
When the subject/object in the first sentence 
(Principle clause) becomes the object in the second sentence 
(dependent clause) remove the object in the second sentence 
and use the relative pronoun que to join both the sentences.

Remember that the relative pronoun que must be placed
immediately after the antecedent and the relative pronoun 
que must be followed by subject pronoun.
Word order = ……….. antecedent + que + subject pronoun ………….
Je lis              le livre   que   j’achète.
                    le livre + que + je
Word order = ……….. antecedent + que + subject pronoun ………….