There are two answers to this question, because it really depends on what you're writing for. Most of the time it's fine to use one space between sentences, but professionally you're supposed to put two spaces between sentences.
It is recommended to use only one space after a period before starting the next sentence. This standard has become widely accepted in modern typography and word processing.
In journalistic writing, only one space. In all other writing, two spaces.
Typically, only one space is used between a period at the end of a sentence and the beginning of the next sentence in modern writing practices. Older typewriting conventions used two spaces, but single-spacing has become the standard in most writing styles today.
How many spaces do you need after the word period? Is she having her period.
1 space.
one space after and abberviation two spaces at the end of a sentence
It is recommended to use only one space after a period before starting the next sentence. This standard has become widely accepted in modern typography and word processing.
Normally two spaces indicates the end of a sentence.
Commas do not go at the end of sentences. Periods go at the end of sentences. Generally when typing on a computer, you should have two spaces after the period at the end of a sentence.
no spaces
2 Spaces
In typing, proper style is 2 spaces after a period (.), as well as after a colon (:).
In journalistic writing, only one space. In all other writing, two spaces.
Unlike the period at the end of a sentence (which have one or two spaces), the period following an abbreviation only needs one space. This is the general rule for abbreviations such as Dr., Jr., or Sr.
It used to be 2 spaces but nowadays it is only 1.
one
0 spaces before and after a dash