7. A semicolon can replace a period.
Using a semicolon can maintain a thought between two separate sentences. Two sentences: The puppies were so cute. They were all adopted by noon, become one sentence with a semicolon: The puppies were so cute; there were all adopted by noon.

8. Use a semicolon before words and terms such as namely, however, therefore, that is, i.e., for example, e.g., for instance, etc.
Transitional phrases usually start a new sentence; the semicolon blends them together with the previous thought. Merging two sentences with a semicolon provides a smoother transition: Weather delayed the flight; therefore, I barely made the meeting in time.