The phrase "a very difficult topic" is correct and usable in written English.
You can use it when discussing subjects that are complex or challenging to understand or address.
Example: "In our next class, we will tackle a very difficult topic that requires careful consideration and analysis."
Alternatives: "a highly challenging subject" or "an extremely complex issue".
He said: "To be fair to John McDonnell, this is a very difficult balancing act, and a very difficult topic.
"It's a very difficult topic to broach with most patients because they feel guilty," Dr. Videtic said.
"We are frequently asked to speak on the subject of Italy, but this is a very difficult topic," the Pope said.
As I indicated in section 2.2, how to distinguish the two readings with reliable empirical tests is an interesting yet very difficult topic, which I do not address in this paper.
There are some amazing writers like Jhumpa Lahiri and Chimamanda Ngozi Adichie who have addressed the challenges of assimilation and inherent culture clashes of immigrants with their remarkable novels, and often with a sense of humor around some very difficult topics with their remarkable novels.
I say that as someone who is Jewish – who grew up in a culture with incredible empathy and engagement with very difficult topics.
As in the Scottish referendum on independence in 2014, he says, this vote represents a "great festival of democracy" on a very difficult and divisive topic.
However, the objective of this qualitative research was to find a small sample of very knowledgeable participants to provide an in-depth exploration of a very difficult and under-researched topic.
Beginning students of these subjects, however, have a very difficult time connecting the topics that they learn in a typical introductory physics course sequence to their chosen college major and career path a source of great frustration to their instructors!
This is a very difficult area to study effectively, but it is an important topic.
