Both can be correct depending on how it's used.
1.What did he fail? (More natural)
He failed the exam.
Where did he fail? Which area did he fail?
He failed in the exam.
(But he did well in his classwork and attendance)
July 18, 2020
1
3
1
He failed the exam (without the preposition 'in').
July 18, 2020
0
1
0
He failed the exam
July 18, 2020
0
0
Still haven’t found your answers?
Write down your questions and let the native speakers help you!