Most people know that a text and a cover letter are different. Far fewer can say what the difference is made of, which is why the advice “be professional” produces so many messages that are formal in the wrong places and casual in the wrong ones. The conventions are specific, and they come from how each thing is actually read.
Text or Chat Message
How it is read: immediately, on a phone, in the middle of something else.
- One idea per message. Two questions in one text reliably gets one answer.
- No greeting needed in an ongoing thread; a greeting on a first-ever message to someone still is.
- If it needs to be read twice, it should have been an email.
- Nothing that a screenshot would embarrass you — a text has no privacy guarantee.
How it is read: in a list, alongside forty others, by someone deciding in one second whether to open it.
- The subject line is not a title, it is the whole message compressed. “Question” is a wasted line; “Absent Thursday — can I hand in Friday?” is not.
- The ask goes in the first two lines. Background goes underneath it, not before it.
- One topic per email. A second topic gets a second email, because replies get filed by subject.
- Sign off with a name. An unsigned email from an unfamiliar address is a small puzzle you have handed the reader.
Formal Letter
How it is read: alone, deliberately, often as a record that will be kept.
- Context first, ask second — the reverse of an email, because there is no list to compete with.
- Full forms throughout: no contractions, no abbreviations invented in the last decade.
- Dates written out, names spelled correctly, an explicit statement of what you are asking for.
- It will be read by someone you did not send it to. Write it for that person as well.
Résumé
How it is read: scanned in seconds, then either read properly or dropped.
- Structure over sentences. Consistent headings, consistent dates, consistent order.
- Verbs first, and concrete: “ran the school fundraiser” beats “was responsible for helping with fundraising activities”.
- No first person, no full paragraphs, no adjectives about yourself that you cannot evidence.
- Every line answers “so what did that produce” or it comes out.
The Conventions Are Not Arbitrary
It is tempting to file all of this under etiquette — arbitrary rules invented by people who care about arbitrary rules. Every one of them, though, comes from how the thing is physically read.
Subject lines matter in email because email arrives in a list and does not in a chat thread. Résumés use fragments because they are scanned, and full sentences slow scanning down. Formal letters open with context because there is no inbox competing for the first line. Change how the thing is read and the convention changes with it — which is why the rules for a medium invented five years from now will be predictable rather than memorised.
This is also the reason “just be professional” fails as advice. It names a feeling. The conventions name what the reader’s eye is doing.
The Mistake Almost Everyone Makes Once
Sending the right content in the wrong container. A three-paragraph explanation as four separate chat messages. A one-line yes-or-no question as a formal letter. An apology to a customer as a public reply under their complaint.
None of these is rude and all of them cost something. The chat version gets read in fragments and answered in fragments. The letter version makes a two-second question take three days. The public apology hands the whole audience a copy of the problem.
One question catches most of it before sending: where will this be read, and what else will be on the screen next to it?
Public Social Post
How it is read: by an audience you did not choose, possibly years later, possibly out of context.
- Assume permanence. Deleting removes it from your account, not from other people’s screenshots.
- Assume the least charitable reading is the one that travels.
- Anything about a named person is a message to that person, whether or not you tagged them.
- The casual tone is fine. The casual judgement about what to publish is what causes the damage.
These five mediums are the ones covered by the professional-conventions subscale of the Communication Adaptability test, scored separately from audience adaptation — because knowing who you are writing to and knowing what the container expects are two different pieces of knowledge, and people commonly have one without the other.