Question

Anytime that you are combining two simple sentences to write one complex sentence it will have a subordinate conjunction is this correct.
Example> The Lydians began the use of money in 700 B.C.before they invented coins.
The first sentence was The Lydians began the use of money in 700 B.C. They invented coins.

Answer 1

Yes. You are correct. :)

Answer 2

Which one is the run-on sentence:

A) Don't run around.
B)after the store don't run around.
C)after the store.