A full stop is used to show that you have come to the end of a sentence. We use sentences all the time. It can be difficult, however, to define one exactly.
In its simplest form a sentence is a group of words that can stand on its own and make sense. A sentence must have a subject and a verb. A sentence always begins with a capital letter and always ends with a full stop. In its simplest form a sentence might look like these:
The dog barked.
The dog barked at the postman.
Full stops are also used to show that you have shortened or abbreviated words. There are two types of abbreviations that use full stops…
You can put a full stop after the first letter of each abbreviated word:
A.A. – Automobile Association.
R.S.P.C.A. – Royal Society for the Prevention of Cruelty to Animals
A full stop can also be used after a selected group of letters from a word to show that the word has been abbreviated:
Aug. – August
Dept. – Department
Ltd. – Limited
Sgt. – Sergeant