Two sentences can carry the same information and feel completely different.
The committee has reached a determination regarding the proposal.
The committee decided on the proposal.
The first is formal. The second is neutral. Neither is wrong, and in the wrong context either one fails. A legal opinion written in the second register sounds careless; a friendly email written in the first sounds like a threat.
Tone is mostly a matter of vocabulary, and vocabulary choices are learnable.
Three registers, not two
It helps to think of English vocabulary as three layers, each with a different history and a different feel.
Formal words tend to come from Latin and French: commence, terminate, inquire, sufficient, assist, purchase, residence. They are longer, more abstract, and more distant.
Neutral words are the everyday core of English, mostly Anglo-Saxon with some borrowed words fully absorbed: start, end, ask, enough, help, buy, home. They are shorter, more concrete, and more direct.
Casual words are colloquial and often figurative: kick off, wrap up, check in, grab, snag, hang out. They are warm and specific and they date quickly.
Most writing lives in the neutral layer with formal or casual accents. A document written entirely in one layer feels flat; a document that switches layers without reason feels unstable.
The same idea in three registers
| Formal | Neutral | Casual |
|---|---|---|
| commence | start, begin | kick off |
| terminate | end, stop | wrap up |
| inquire | ask | check in |
| sufficient | enough | plenty |
| assist | help | give a hand |
| purchase | buy | pick up |
| residence | home | place |
| obtain | get | grab |
| inform | tell | fill in |
| approximately | about | around |
The table is not a set of synonyms to swap freely. Each column carries a different relationship with the reader. Formal vocabulary signals distance and procedure. Neutral vocabulary signals clarity and equality. Casual vocabulary signals familiarity, which is only appropriate when familiarity exists.
Matching register to document
Different documents have different default registers, and choosing the wrong one is a bigger error than choosing the wrong synonym.
Academic writing is formal, with neutral verbs wherever possible. "The study examines" is better than "the study looks into," and both are better than "the study investigates the phenomenon of."
Business reports are neutral with formal structure. Short sentences, concrete nouns, and standard headings. Formality comes from the organisation, not from the vocabulary.
Legal and regulatory text is formal because precision outweighs readability, and because terms have defined meanings that a plainer word would lose.
Marketing and web copy is neutral to casual, depending on the audience. "Buy now" beats "purchase immediately" in almost every context.
Email follows the relationship. A first email to a stranger is neutral-formal; a reply in a long thread is casual. The register should match the relationship, not the writer's mood.
Personal writing can be any register, as long as it is consistent.
The formality traps
Nominalisations. Formal writing loves abstract nouns. "The implementation of the policy" is more formal than "implementing the policy" and also harder to read. Use the formal version when the abstraction is the subject, and the verb version everywhere else. The zombie nouns guide covers the trade-off.
Latinate verbs where a plain one exists. "Utilise" for "use," "facilitate" for "help," "endeavour" for "try." These are not wrong, but they add distance without adding precision, and readers often read them as insecurity.
Hedging. "It could be argued that," "to some extent," "it may be the case that." Formal writing uses hedges to be accurate; casual writing uses them to avoid commitment. The same phrase can be either, and the reader can usually tell which.
Contractions. "Don't" and "can't" are neutral in most modern writing and formal in none. Academic and legal text usually avoids them; business writing increasingly uses them.
The casual traps
Slang that dates. "On fleek," "bae," "lit" — casual vocabulary has a shelf life measured in months. Unless the writing is meant to be dated, prefer colloquial words that have lasted: "a mess," "a pain," "figure out."
Jargon dressed as plain speech. "Let's circle back and unpack the deliverables" is casual in grammar and corporate in vocabulary. It is the worst of both registers: informal enough to sound unserious, obscure enough to exclude.
False intimacy. "Hey friend!" from a company that has never met the reader. Casual register implies a relationship; using it without one reads as manipulation.
Over-familiar verbs in serious contexts. "We killed the project" is vivid and informal. In a board paper, "we cancelled the project" is the right choice, not because it is more formal but because the vividness distracts from the decision.
Keeping a document in one key
The practical method is simple. Before writing, decide the register, and write one sentence at each extreme to calibrate.
Formal: The review identified three areas requiring further investigation. Casual: We found three things that need a closer look.
Then choose the middle version that matches the document. "The review found three areas that need more work" is neutral and works in most business contexts.
When editing, read the document once looking only at register. Mark any word that belongs to a different layer from the paragraph around it. Most documents have five or ten, and fixing them makes the voice consistent without making it flat.
The test
Read a sentence aloud and ask who it sounds like it was written for. If the answer is "a institution" when you meant "a person," the register is too formal. If the answer is "a friend" when you meant "a client," it is too casual.
Register is not about being impressive. It is about being appropriate, and appropriateness is the larger part of style.