Since I'm in a weird mood today:
"." This is a period. It goes at the end of a sentence.
"," This is a comma. It goes where you would normally pause when speaking.
" " This is a space. Put two after a period and one after a comma.
A B C These are upper case letters. They are used to start a sentence and in special circumstances like I (as in me).
a b c These are lower case letters. They are useful in other places besides the start of sentences.
The use of all of the above makes reading a post much easier.
