Within Business, it is crucial that the user is articulate in their use of terminology using connectives and punctuation professionally.
You are emailing your manager to request for some time off, you will need to think carefully about how you structure sentence and use words. Because you want to come across in a civilized manner to your employer. Underneath is an example of how I would personally contact my boss regarding the above issue.
When messaging with friends and family. The discipline of using correct grammar is subdued and you can speak in a casual tone. When texting, words are abbreviated and phrases are spelled out as initials. In the message underneath my friend uses the term “yo” which is something that would stand out as very unprofessional in a business email.