I want to learn how to write professional looking letters so I have to learn how to use punctuation and stuff properly. As silly as it seems, I still don't know when and where to use commas. I used to not know how to use them at all but someone advised me to sound out the sentence in my head and then wherever theres a pause, put in a comma. That works to a degree but I'm still not fully sure. Lets say I'm writing a letter with this sentence "Hello, I am contacting you on behalf of my client John Doe". I notice theres a pause in between client and John Doe so should I put a comma in there (e.g. "on behalf of my client, John Doe") or is there some other symbol I should use? I also don't really know how to use paragraphs. I just haphazardly throw them in whenever I feel like it. For example I threw in a paragraph there to make this thread easier to read but the reason I chose that particular place to put it in was cuz this is my 2nd question. Is that the correct way to use paragraphs i.e. to separate different elements of the text? What happens when you've written a lot but you can't see any logical way to divide it cuz it all seems to be part of the same element?