one
In traditional English writing, there are two spaces after a period.
In journalistic writing, only one space. In all other writing, two spaces.
no spaces
2 Spaces
In typing, proper style is 2 spaces after a period (.), as well as after a colon (:).
It used to be 2 spaces but nowadays it is only 1.
2
2
one space after and abberviation two spaces at the end of a sentence
One space follows a period after an initial.
One.
1