How we change what others think, feel, believe and do
End of sentence
The humble dot is too easy to use. Just put it at the end of sentences.
Use it to create finality of something said.
Use it also in abbreviations. An informal short-cut here that is often used is to use one period when two should be used. Thus eg. rather than e.g., qv. rather than q.v. etc. Sometimes, the period is completely omitted, such as 6am rather than 6 a.m.
Hello. My name is Dr. Who, Ph.D.
In abbreviations, the period signals that there are letters missing.
When you are typing, the English convention is to put two spaces after the period. In the USA, the rule is only one space. This is interesting in that a larger space hints at taking a longer pause, which of course you do after a period (longer, at least than a comma).