Semicolons before transitional phrases
 
A transitional phrase (e.g., however, as a result, consequently) will usually start a new sentence. However, if you would like a smoother transition between the first sentence and the one starting with the transitional phrase, you can use a semicolon before the transitional phrase. You cannot use a comma.
 

Semicolon before a Transitional Phrase

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 of the sentence. The bridge is known as a transitional phrase. There is always a comma after a transitional phrase but not before.

A transitional phrase will usually start a new sentence, but if you would like a smoother transition than that afforded by a full stop / period, you can use a semicolon before a transitional phrase to merge the new sentence with the previous one.

Examples (transitional phrases shown in bold):

  • 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 has 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.
 

START A NEW SENTENCE NINE TIMES OUT OF TEN

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 a smoother transition. You should not do this too often.

DEFINITELY NOT A COMMA 


You cannot merge two sentences 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 or run-on error. This error is most commonly seen with the word however.

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

See also:

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