Semicolons before transitional phrases

Use a semicolon before transitional phrases.

1. This point is closely related to the lesson "extending a sentence with a semicolon" as it concerns merging two sentences to form one. However, in these examples, there is a short bridge between the first half and the second half. The bridge is known as a "transitional phrase". There is always a comma after a transitional phrase. (The transitional phrases are shown in bold below.)

Examples:

Everyone knows he is guilty; of course, it will never be proved.

(The transitional phrase "of course" acts like a bridge between the first half and
the second half.)

Sarah's guest was turned away by the doorman; as a result, she left before the presentations.

("as a result" - transitional phrase)

Business is booming; for example, Siemens have made 10 orders since
4 o'clock.

("for example" - transitional phrase)

I missed the early plane; however, I still made the meeting.

("however" - transitional phrase)

The paper is stuck in the lift; consequently, we cannot finish the printing.

("consequently" - transitional phrase)

She does not loathe chess, on the contrary, she quite likes it.

(The term "on the contrary" is a transitional phrase. You cannot merge two
sentences into one with a comma. You must either start a new sentence or
use a semicolon.)

My security guards are not trained in fire-fighting; therefore, we paged the
fire service.

DEFINITELY NOT A COMMA

Transitional phrases are common. Most of the time, a transitional phrase will start a new sentence. However, you can use a semicolon if you wish to bring it closer to the original sentence. You cannot do this with a comma. This is a very common mistake.

It is extremely foggy, nevertheless, the game will be played.

MAIN CULPRIT IS "HOWEVER"

The error described above is called a "comma fault". This error is most commonly seen with the word "however".

I am leaving on Tuesday, however, I will be back on Wednesday to collect my wages.

I am leaving on Tuesday; however, I will be back on Wednesday to collect my wages.

I am leaving on Tuesday. However, I will be back on Wednesday to collect my wages.

COMMA AFTER "SO"

When the word "so" is used to mean "therefore", it is a transitional phrase and should be followed by a comma.

We are not in a position to fund the changes. So, the current system will remain until at least April when it will be
reviewed again.

Associated lessons:

Commas after a transitional phrase
Extend a sentence
Using semicolons before conjunctions (and, or, but, etc.)
Using semicolons in lists
Using semicolons to extend a sentence