Period
A period is used to end sentences, just like in Russian, and to designate file extensions. The following rules refer to English and are really noteworthy.
With abbreviations
A period is used with some abbreviations, and always with those abbreviations that would look like a word otherwise.
a.m.
U.S.
In lists
When a colon introduces a bulleted list, use a period after each entry if it is a complete sentence or a phrase that completes the introduction.
The database owner can:
* Create and delete a database.
* Add, delete, or modify a document.
* Add, delete, or modify any information in the database.
Do not end the entries with periods if they are all short phrases (three words or fewer).
The database includes:
* Reports
* Forms
* Tables
Mr. vs. Mr
British people usually write abbreviations without full stops in modern English.
Full stops are normal in American English.
Mr (AmE Mr.)= Mister, kg (AmE kg.)= kilogram, Ltd = limited (company)