Common Mistakes : Difficulty

noun

.BAD: She had a difficulty in obtaining a visa
.GOOD: She had difficulty (in) obtaining a visa

: (have difficulty/difficulties (in) doing sth (NOT a difficulty
.Sometimes he has difficulty in making himself understood

.BAD: I have great difficulty to understand him
.GOOD: I have great difficulty (in) understanding him

: (have difficulty/difficulties (in) doing sth (NOT to do
.You should have no difficulty in passing the exam