I'm wondering what prepositions to use after "assist someone." It seems there is a choice between "in" and "with," but I don't know if they are freely interchangeable. If they are interchangeable in particular sentences, is there any subtle difference?
- You will be employed to assist in/with the development of new equipment.
- Two men are assisting the police in/with their enquiries.
- We are looking for people who would be willing to assist in/with the group's work.
- Another doctor assisted him in/with the operation.
- A senior academic would assist him in/with his work.
- The cream assists in/with the prevention of skin cancer.
Could it be that "in" followwed by a noun (phrase) suggests that work of a more general nature is involved, whereas "with" suggests more specificity, tied to a paritcular task?