People search for a prefix for name when a title crosses their path. A form asks for a salutation. An invitation prints a word in front of someone’s name. A colleague signs a letter with Ms. or Mx., and you want to know whether that word belongs in front of the name you are about to type.
Most of these searches come down to one decision, which word goes before this person. The answer depends on what the title signals, whether you know the person’s own preference, and which style guide the document follows.
This guide covers the titles you will actually use, the words that go after a name instead, the capitalization and punctuation rules that trip people up, and how to tell a title from a surname element.
In this guide
- What a prefix for name means
- The courtesy titles you will use most
- Titles for doctors, lawyers, clergy, and military ranks
- Job titles and elected office before a name
- Degrees and other words that follow a name
- Married names, family titles, and names you do not know well
- Name parts that attach to a surname
- Capitalization and punctuation rules worth memorizing
- How to choose the right prefix for the person in front of you
- Frequently asked questions
- The short version
What a prefix for name means
In American English, a prefix before a name almost always means a title or honorific. Mr., Dr., Rev., and Capt. are the everyday examples. Each one signals something, usually a profession, a rank, or simple courtesy.
Two questions follow: which word fits this person, and how should you punctuate it.
There is a second meaning of prefix worth knowing, because some searchers mean it. Inside a surname, a prefix is a word element joined to the family name. Mc, O’, de, and Von are the ones Americans meet most. Those attach to the name itself rather than standing in front of it. Everything between here and the FAQ section uses prefix in the title sense.
The courtesy titles you will use most
These five cover the large majority of real situations. They carry no profession, only how you refer to the person.
| Title | What it signals | How to use it |
|---|---|---|
| Mr. | Male, marital status not indicated | Before a first name, a middle name, or a last name alone |
| Mrs. | A woman who is or was married | Before her own last name or full name |
| Ms. | Female, marital status not indicated | Before a full name or a last name alone |
| Miss | Traditionally a girl or unmarried woman | Adults usually prefer Ms. or Mx. instead |
| Mx. | Neither gender nor marital status | Any person may use it, and anyone may be addressed with it |
Ms. is the workhorse. It has been common in North America since the 1970s as a title that says nothing about marriage, and it is now the default for a woman whose marital status or preferred title you do not know. The Language Portal of Canada makes that point plainly: because Ms. reveals no marital status, it works with any woman’s name unless she has told you she prefers something else. The Emily Post Institute repeats the same rule.
Miss is the one to watch. It is not wrong, but for an adult it lands as old-fashioned or patronizing often enough that using it is a small social risk. Reserve it for girls, and follow an adult’s lead if she uses it for herself.
Mx. is a real title of courtesy now. Merriam-Webster lists it as a gender-neutral title used for people who do not wish to state their gender, notes that it was suggested in the late 1970s as a way to avoid revealing gender in a title, and observes that it is mainly a written form. That last detail matters. Expect to read Mx. far more than you hear it.
When you name several people at once, you can repeat the singular title before each name for a short list. In formal writing with more than three names, put the plural once at the front: Messrs., Mmes., Mses. or Mss., and Misses.
Titles for doctors, lawyers, clergy, and military ranks
These titles mark a credential or an office. Use them when the credential is the reason the person matters in what you are writing.
Dr. is the most overused of the group. Federal writing guidance is explicit that Dr. belongs to medical doctors and not to people who hold a doctorate, and the HRSA web style guide spells out that rule along with a second one worth keeping. Include a professional title only at the first mention of a name, and only when it is relevant to what you are saying. A doctor’s credential helps when you discuss medicine. It does not help when you are thanking someone for a gift.
Rev., Fr., Rabbi, Imam, Pastor, and Sister come before a clergy member’s name. A nun’s Sister is an honorific that travels in front of the name, and it collides with the Sr. suffix for a senior family member. When both could apply, context settles it. “Sister Mary Anthony” is a nun. “Robert Sr.” is a father.
Capt., Lt., Col., Gen., Adm., Sgt., and Pvt. come before military rank and are written with periods. Full names get the rank too, though it reads stiffly: “General Dwight D. Eisenhower” is correct and “General Eisenhower” is what most readers prefer.
Esq. is the traditional marker for a lawyer. It is legal in American English and still expected in some bar settings. Elsewhere it adds length without adding meaning, and the federal guidance above treats a lawyer’s designation as beside the point unless the subject is legal.
Job titles and elected office before a name
Office titles split into two groups under common American style practice. Some are abbreviated before a name, and the rest are spelled out.
Abbreviated before a name: Dr., Gov., Lt. Gov., Rep., Sen., and military ranks such as Pvt.
Spelled out in every use: Mayor, Governor when it modifies a place rather than a person, Judge, Professor, Officer, Detective, and Chief Justice.
The rule behind the split is capitalization. A title sitting directly in front of a name is part of the name, so it gets capitalized and usually an abbreviation. The same title standing alone is a job description, so it is lowercased and spelled out. Write “Senator John Casey,” then “the senator from Ohio spoke for an hour.” The Writing Explained summary of AP style lays out this pattern and notes that long titles are set off from the name with commas, as in “Frank Kendall, the undersecretary of defense for acquisition, technology, and logistics, met with us.”
Two more habits are worth stealing. When a title belongs to exactly one person in an organization, wrap it in commas and add the word the, which gives you “Jim Jones, the managing editor, spoke about it.” And skip the country abbreviation on domestic titles, so it is Secretary of State John Kerry in a US story and U.S. Secretary of State John Kerry in an international one.
Degrees and other words that follow a name
Some markers belong after the name rather than before it. PhD, MD, JD, RN, PA, and the professional postnominals fall here.
Before you reach for one, ask whether it helps the reader. Government guidance puts it plainly: use the degree relevant to the subject matter, and only at the first mention. Listing a wall of letters after a name reads as padding and is the reason many people drop them entirely.
Periods are the part that gets argued over. The federal guide above writes degrees with periods, giving Ph.D. and M.A. as examples. The MLA Handbook sets them without periods as PhD and MA, and other publishers land somewhere between. There is no single correct answer for an American reader. Pick a guide, follow it in the document, and stay consistent.
Generational suffixes follow the same consistency rule. Jr., Sr., II, III, and IV all take periods under most American guides, and most are reserved for names that run in a family, such as a father and son with the same full name. Once you start writing them, keep the punctuation consistent for the whole line.
Married names, family titles, and names you do not know well
The traditional rules here are older than most people expect, and the modern version is simpler.
A married woman may use Mrs. with her own name, which is the usual choice now. She may also use Mrs. with her husband’s full name, a form that was once standard. And she may use her own surname for everything, married or not. None of these needs an explanation unless you are writing a formal announcement.
A widow is the case etiquette guidance still handles carefully. Mrs. remains traditional and preferred unless the widow has told you she prefers something else. This is one of the few places where the conservative form is genuinely the courteous default, because it signals continuing connection rather than a search for a new partner.
Divorce leaves more room. Ms. and Mr. with each partner’s own name is the most common choice, and Mrs. is still in wide use. Whatever the woman chooses is normal.
And the safest option stays available in every case. When you do not know someone’s title, do not guess. Use their full name with no title at all. A name on its own is never an error. A wrong title is.
Name parts that attach to a surname
Now the other meaning of prefix. These are word elements bound to a family name, not titles, and they take no period.
Mc and Mac mean “son of” in Irish and Scottish surnames. McDonald, MacLeod, and McCarthy all follow this pattern, and the element is capitalized when the rest of the name is.
O’ marks descent from in Irish names. O’Brien, O’Neill, and O’Connor take an apostrophe because that is how the word attaches.
De, della, di, da, la, le, and van appear in Italian, Spanish, Portuguese, French, and Dutch surnames, usually in lowercase. De La Cruz, van der Berg, and da Silva are correct as written, and capitalizing every element is a common and visible mistake.
Bin and ibn mark parentage in Arabic names, so bin Rashid and ibn Khaldun identify a son. Al- is different. It is the Arabic definite article and is usually written attached and lowercase, as in al-Khwarizmi.
Von shows noble descent in German names and is written lowercase in running text. Capitalization varies by family, so follow whatever the person uses on their own name. That is the only reliable rule in all of this section.
Looking up a family name rather than a person, search these elements, not honorifics.
Capitalization and punctuation rules worth memorizing
Six rules carry most of the weight.
- Capitalize a title directly before a name, and abbreviate it if the abbreviation is standard.
- Lowercase and spell out the same title when it stands alone or is set off by commas.
- Put one period after an abbreviation, and never two. Mr. Smith, not Mr.. Smith.
- Leave a space after the period, then the name.
- Use commas to set a long title away from the name.
- Keep these titles abbreviated even in dialogue and fiction. The Chicago Manual of Style answers this directly: social titles are almost always written in their shortened form before a name, and Ms. is pronounced “miz”, so there is nothing for the reader to work out. Write Ms. Smith, not Miss Smith, even in a script.
How to choose the right prefix for the person in front of you
Use this order of decisions and you will rarely guess wrong.
- Check how they sign their own name. Email signature lines, business cards, and professional profiles are the best evidence available. Whatever they use is what they want.
- Ask once, plainly. “What should I call you?” settles the question permanently.
- Default by situation. For a woman whose status and preference you do not know, use Ms. For a man, use Mr. Use Mx. when that is the person’s own title or clearly the right neutral choice.
- Add a professional title only when it is relevant. Dr. earns its place in a health story and adds nothing to a thank-you note.
- Drop the title once you are on first-name terms. Courtesy titles can look stiff between colleagues who use first names anyway.
- Leave titles off mailed addresses. The USPS addressing standards tell mailers to remove gender words such as MS, MRS, MISS, and MR, and title words such as DR, PHD, DDS, and RN, from addresses.
- Write the name the way the person writes it. Spellings, middle names, hyphens, and capitalization are theirs to set.
Frequently asked questions
What prefix do I use if I do not know someone’s marital status?
Use Ms. for a woman and Mr. for a man. Both say nothing about marriage, which means neither can embarrass the person. If you are unsure of anything at all, leave the title off.
Is Miss still an acceptable prefix?
It is acceptable, though many adult women find it unwelcome. Keep it for girls. When an adult uses it for herself, follow her lead without comment.
Do I spell out titles in dialogue or a script?
No. Write Ms., Mr., and Dr. in their shortened forms even when the line is spoken out loud. Ms. is pronounced “miz”, so the abbreviation costs the reader nothing.
Should a prefix go on a mailed address?
Leave it off. Postal addressing standards treat courtesy and professional titles as removable words, and a name alone delivers just as reliably.
Is it Ph.D. or PhD?
Both are used in American English. Federal web guidance uses periods, and the MLA Handbook does not. Choose the one your guide or publisher uses and keep it steady.
Can I skip the prefix entirely?
Yes, and it is often the best choice. A full name with no title reads as confident and neutral. Titles help in formal settings and hurt in casual ones.
What if someone uses a title I do not recognize?
Use it. Copy it from their signature and match the punctuation. Looking up a title before using it costs you a minute and saves you from getting it wrong in writing.
The short version
Prefixes before a name are titles, and most of the time the right one is simple. Ms. and Mr. when you know nothing else. Mx. when that is the title the person uses. Dr. when the credential matters to what you are writing. Nothing at all when you are unsure.
The single best habit is to notice how the person writes their own name and then copy it. That approach beats every style guide, including this one.