Difficulty + in + gerund
There are certain expressions which are never followed by the infinitive. They always take a gerund after them.
Incorrect: I have no difficulty to do it.
Correct : I have no difficulty in doing it.
Difficulty + in + gerund
There are certain expressions which are never followed by the infinitive. They always take a gerund after them.
Incorrect: I have no difficulty to do it.
Correct : I have no difficulty in doing it.