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The usage of colon and semicolon is often confused. Go through the differences between the usage of colons and semicolons to help you make out the dissimilarity between these punctuations.

Colon Vs Semicolon

English language can be quite complex and punctuation is a powerful aspect of the language. It strings the words in the correct manner, giving them the right meaning. Good writing in English makes use of punctuation in the proper places. So, knowing where and how exactly to use these punctuations is extremely important. The colon and semicolon stand as a troublesome pair with their usage often confused. The colon and the semicolon are not for merely decorating a sentence but their literary importance is quite evident in the fact that they can completely change or modify the meaning of sentences. While the colon comprises of two dots placed vertically above each other, the semicolon is a comma with a dot placed on top of it. Similarly, the way they are used is quite different too. The examples and points listed below should help you to correctly identify how they should be used and the effect they have on sentences.

Difference Between Colon & Semicolon

Semicolon Usage

Semicolons are used commonly in English. It is a linking punctuation between two closely related sentences. They are so closely related that the full stop is often skipped for the semicolon. The gist of the main uses of semicolons is given below.
Colon Usage
The colon is an important punctuation. It introduces the reader to sentences. The presence of a colon hints towards something important being stated. After reading the sentence before the colon, the reader anticipates some amount of useful information. The gist of the major uses of colons is listed below.
Colons are also used in salutation of business letters (Dear Mr Luke:_), in the heading of a business memos, letters (To:_, Subject/Title:_) and between the hour and minutes notation (6:15PM). Some other places where colons are used is in citation of works in literature, in between verses of Bible etc. E.g. Genesis 1:18-20 or Vol. 2:34.

Where The Confusion Arises
Although the principles of the two punctuations have been explained, to dissolve the confusion all the more it makes sense to contrast them with the help of examples.

Consider the following sentences:

Example #1

Lisa is upset. Gus is having a nervous breakdown.

These two sentences, separated by a full stop, don't suggest any kind of connection but just inform the reader of two bad situations.

Lisa is upset; Gus is having a nervous breakdown.
When a semicolon is introduced, a particular relation arises between the two sentences. The two disjointed yet related thoughts are combined.

Example #2

I have the answer. Mike's solution doesn't work.

These two sentences, separated by a full stop, do not imply anything. They just state two facts directed towards different problems. A sense of similarity or connectivity does not arise at all.

Now with a semicolon;

I have the answer; Mike's solution doesn't work.
After these two sentences are separated by a semicolon, a relation is introduced between the two independent clauses. The meaning that can be inferred is that Mike and I are working on the same problem.

I have the answer: Mike's solution doesn't work.
Finally, with a colon, the meaning that the sentence implies is that 'the failure of Mike's solution' is the answer which has been obtained.

Understanding these examples helps bring out the differences between a colon and a semicolon. To summarize, a semicolon is used to join two sentences which would otherwise be joined by 'and', 'or', 'but', 'yet' or 'while'. However, a colon is used to separate a general statement from the following specifics. Also, a semicolon cannot be used to introduce quotations or lists. So as you saw, these symbols can have different meanings on sentences and they are not interchangeable punctuation marks. They should hence be used to in a proper manner rather than arbitrarily or even interchangeably.