"difficulty in explaining" is a correct phrase in written English.
It is typically used when describing challenges or obstacles one faces when trying to explain something. Example: "Despite my best efforts, I experienced great difficulty in explaining the complex concept to my students."
The doctor has no difficulty in explaining why this patient captures his attention.
The BBC may be forgiven for having difficulty in explaining this staggeringly unequal conflict in all its complexity.
The public row with Mr. Barak illustrated the magnitude of Mr. Netanyahu's retreat and his difficulty in explaining it.
All want to leave Nuremberg as urgently as a dental patient enduring the drill wants to get up and leave the chair; and they would have difficulty in explaining the cause of that urgency.
Where all this leaves the replacement of Trident and the Royal Navy's two supercarriers - two hugely expensive projects, surely both irrelevant in the fight against terrorism - the SDSR will have difficulty in explaining.
Among those to tweet their confusion was the Washington Examiner comment editor Philip Klein: While the actor Frances Barber admitted her difficulty in explaining the nuances of the affair to her American friends: So how would you explain to someone from outside Britain why Thornberry's position became untenable?
Joe Andrew, the national chairman of the Democratic National Committee, held a news conference here to unveil plans to use television advertisements, Web sites and roadshows to criticize Mr. Bush's record in Texas and his occasional difficulties in explaining his policies.
While analysts were generally impressed by the near-term revenue growth, the company's difficulties in explaining clearly what is happening in its business sales drew intense scrutiny from financial analysts.
Due to the difficulties in explaining what sleep actually is and the lack of research outside of birds and mammals, scientists tend to be a little hesitant when attributing the word sleep to reptiles, fish and especially invertebrates, and prefer to use the term rest instead.
Locke then went on to conjecture that it might be just as easy for God to add the power of thought to a system of matter organized in the right way as for God to connect an immaterial thinking thing to a body (ibid).. Clearly, the difficulties in explaining how an immaterial mind could relate to a material body play a significant role in leading Locke to this position.
