a) Soshite and sore kara are very similar in both meaning and function. When describing a chronological relationship, they both mean “and” or “then.” However, sore kara expresses the fact that the second clause is a completely separate action to and occurring directly after the first.  Soshite, on the other hand, implies a loose connection between two sentences or clauses.

b) Sore ni means “besides” or “moreover.” It is used to introduce an aside or some new information that supports what one has just said.

c) Sore de is used to introduce or state the logical result of a previously mentioned statement or situation. It can loosely be translated as “(So) that’s why…”