While a semicolon connects two independent clauses, it doesn't clarify how their ideas are related. Adding a conjunctive adverb helps to clarify the relationship between the two clauses.
The most common conjunctive adverbs (THAMOs) are Therefore, However, Also, Meanwhile, and Otherwise.
Grammar Note: A conjunctive adverb that comes after a semicolon is followed by a comma.
Also, Additionally, In addition: These terms simply introduce an additional thought.
We all saw the bear; also, my sister saw a snake.
Similarly: This term introduces an idea that is similar to the previous.
I may have overreacted to seeing the bear; similarly, my sister overreacted to seeing the snake.
Meanwhile: This term introduces something that occurred at the same time as the previously discussed event.
We ran out of the forest; meanwhile, the bear continued to eat its berries quietly.
Furthermore, Moreover: These terms introduce an additional idea that builds on the previous.
We decided not to go back to that forest again; furthermore, we planned on studying bear avoidance strategies.
Therefore, Thus, Consequently: These terms introduce a conclusion that can be logically inferred based on the previous idea(s).
We saw a bear; therefore, we ran out of the forest.
However, Regardless, Nonetheless: These terms introduce an unexpected contrast or seeming contradiction.
We think it was a bear; however, we didn't stay to find out.
In contrast: This term introduces an idea that contrasts with the previous.
I was terrified of the bear; in contrast, the bear was unbothered by us.
Actually: This term introduces a clarification to correct a previous inaccuracy.
My mom claimed that bears don't usually eat people; actually, they prefer berries.
Otherwise: This term introduces an alternative.
We believed we needed to run out of the forest; otherwise, we might have been eaten.