The semicolon, known as the world's most feared punctuation mark, isn't actually that complicated to use once you understand the basic rules. While it's best known for connecting two independent parts of a sentence that are closely related in thought, it does much more than that and can even be used to give someone a mischievous wink ;)
The sentences before and after the semicolon must be complete, and the two sentences must be closely and logically connected.
| Some people write with a word processor; others write with a pen or pencil. | ✔ |
| I ordered a cheeseburger for lunch; life is too short to count calories. | ✔ |
| The cow is brown, she's also old. | ✘ |
The examples above all consist of two complete, grammatically correct sentences joined together. The third, incorrect sentence contains a comma error; to correct this, you can replace the comma with a semicolon, or add an “and” before the second sentence.
Reference(s).. W&M Writing Resources Center