derrière

In a sentence

• Le livre est derrière la table.

  The book is behind the table.

  Here 'derrière' is used as a preposition to indicate the location of the book in relation to the table.

• Je me suis assis derrière lui dans la classe.

  I sat behind him in the classroom.

  In this sentence, 'derrière' serves as an adverb indicating the relative position of the action in relation to him.

• Derrière ces mots, il y a un profond sentiment.

  Behind these words, there is a deep feeling.

  Here 'derrière' is used metaphorically to suggest an abstract concept hiding behind the literal meaning of the words.