difficile à comprendre
It's difficult to understand his theory.
Il est difficile de comprendre sa théorie.
This novel is difficult to understand.
Ce roman est difficile à comprendre.
It's difficult to understand you.
Il est difficile de vous comprendre.
It's difficult to understand his ideas.
Il est difficile de comprendre ses idées.
His ideas are difficult to understand.
Ses idées sont difficiles à comprendre.
Written in technical terms, this book is very difficult to understand.
Rédigé dans un langage technique, ce livre est très difficile à comprendre.
It is difficult to understand this novel.
Ce roman est difficile à comprendre.
This book is difficult to understand.
Ce livre est difficile à comprendre.
What's so difficult to understand in me?
Qu'est-ce qu'il y a de si difficile à comprendre chez moi ?
— The Asthenic Syndrome (1989)
His poems are difficult to understand.
Ses poèmes sont difficiles à comprendre.