English Grammar Rules & Mistakes: Learn All of the Essentials: Writing, Speaking, Literature and Punctuation Rules Complete with 10 Key Skills and Over 200 Common Error Examples

Making it shorter: understanding abbreviations
So far in this chapter, we have gone through a whole bunch of little words
that literally help us to make sense of our language and communicate clearly.
We really couldn’t do without them. However, there does exist a whole
category of tiny words that are not the result of wanting to be clearer in our
language, rather they have come from the desire to be faster. These are
abbreviations which are shortened versions of words that we commonly use.
As I have previously said, the way we use the English language can
sometimes be a bit contradictory. Sometimes, we are obsessed with making
certain that the meaning of what we are trying to say is translated correctly.
This leads us to use grammatical rules to ensure clarity. Then, on the other
hand, we also like to speak quickly but still convey meaning. The truth is,
there is a time and place for both styles of English language use. For
example, being grammatically correct and using well thought out sentence
structures is essential for the formal use of the English language. Whereas,
using devices such as abbreviations where we shorten words despite
compromising understanding, is much more suited to informal language use.
So, before I demonstrate abbreviations, just remember that if you are trying
to up your formal language game, then you should use them lightly,
particularly in written work.
That being said, abbreviations can be really useful in quickly conveying a
message. Many of them have also become so common that we are much
more accustomed to hearing the abbreviation than we are the full version of
the word or phrase.
Dr. Ramirez is ready to see you. 
The word doctor, in this case, is very commonly abbreviated to Dr. with a
period placed after the abbreviation. It would be odd for us to see it written
out as Doctor Ramirez as this abbreviation is now the accepted norm.
FYI there is a letter for you at reception.

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This abbreviation is an acronym, meaning it has taken the first letter of each
word in the phrase to form it. FYI means for your information. It is
frequently seen in emails between staff members and on social media
messaging sites. However, it is also a clear example of informal language and
therefore must only be used informally. Writing it in a memo to your boss is
certainly not the best way to impress.
N.B. classes will start at 10 am next week.
The final group of acronyms that do make their way into formal language are
those which have come from Latin, then abbreviated and subsequently used
by a majority of those in academia, which in turn have made them common
in all formal writing. N.B. means nota bene which translates as take note.