Sometimes it has happened to me that when I need to write a text quickly I use many words repeatedly as a link with others and it gets quite tedious having to repeat many of those words constantly, such as "Because", "due to", "but"... so without wasting time I started searching the net and found a solution to this that can come in handy on certain occasions, being a simple and comfortable system with the spell checker.
The positive part of all this is that it is an option that is already pre-installed by default within the operating system itself and we will not have to download or install anything else, just follow a few simple steps and we will have everything ready to start using it.
The first thing would be to go to system preferences and look in the second row the Keyboard option.
Once inside the options that it shows us, we must go to "Text" to add the entries we need. For this we will have to click on the "+" button and you are ready to write the abbreviation to be replaced by the assigned word in each of the fields.
After the last step, we will only have to open the text editor and check that all abbreviations work fine and that the proofreader is doing his job correctly (when writing the abbreviation and pressing space, he will automatically have to change to the assigned word).
I agree that not everyone will need it since it can also cause us to get used to writing incorrectly, but as I have said before, it is very practical for those who need that agility when writing a lot of text and time is a fundamental factor in their daily work.
More information - How to disable spell checker easily