I Don’t Know Who That Is In Spanish | Native-Like Phrases

The most natural line is “No sé quién es,” and “No sé quién es esa persona” adds extra clarity when the listener may need it.

If you want to say “I don’t know who that is” in Spanish, the cleanest answer is usually no sé quién es. It sounds natural, direct, and easy to drop into real conversation. You’ll hear it when someone points at a person in a photo, mentions a name you don’t recognize, or asks about someone across the room.

Still, this phrase has a few moving parts. Spanish speakers don’t always build it the same way English does. That’s where learners get stuck. They try to translate each word one by one, and the result comes out stiff. A better move is to learn the version native speakers reach for first, then add detail only when the moment calls for it.

This article breaks down the most natural translation, when to use a fuller version, what changes in casual and polite speech, and which mistakes make the sentence sound off. By the end, you’ll know which line fits the moment instead of guessing.

The Most Natural Way To Say It

The default translation is No sé quién es. Word for word, that means “I don’t know who he or she is,” but in normal use it also covers “I don’t know who that is.” Spanish often leaves out words that English keeps visible. If the person is already clear from the situation, there’s no need to pack the sentence with extra material.

That’s why this short version works so well. Someone shows you a photo and asks, “¿Quién es?” You can answer, “No sé quién es.” Someone points toward a stranger at a table. Same answer. It feels smooth because Spanish trusts the context.

When The Short Version Is Enough

Use no sé quién es when the listener already knows which person you mean. The person may be on a screen, in a photo, in a story, or right in front of both of you. In those moments, the sentence doesn’t need anything else.

That short form also sounds more natural than many “full” translations beginners try first. English likes visible pointers like “that,” while Spanish often lets the situation do that work.

When A Longer Version Sounds Better

Sometimes context is weak. Maybe several people are on screen. Maybe you want to sound a touch more precise. Then you can say No sé quién es esa persona. That means “I don’t know who that person is.” It’s still natural, just more explicit.

You can also say No sé quién es él or No sé quién es ella in some settings, though that usually lands best when you want to stress the person’s identity. In many everyday moments, it sounds heavier than needed.

Why Spanish Uses “No Sé Quién Es”

The sentence works because Spanish leans on structure, not word-by-word matching. The verb saber is doing the job of “to know” in the sense of knowing information. You are saying that you do not know the person’s identity. That is why sé appears here, not a form of conocer.

The word quién introduces the unknown identity. It needs the accent mark because it is an interrogative form, even inside an indirect question. The RAE entry on quién and its note on accent marks in interrogative words back up that spelling.

Then you get es, the third-person form of ser. Spanish uses ser here because you are identifying who someone is, not where they are or how they feel.

Saber Vs. Conocer In This Sentence

This is one of the big trouble spots for English speakers. In Spanish, saber often deals with facts, information, or knowing how. Conocer often deals with familiarity, meeting people, or being acquainted with places and things. The RAE dictionary entry for conocer and the Instituto Cervantes lesson on saber and conocer make that contrast clear.

So if you say No conozco quién es, the sentence sounds wrong to native ears. Spanish does not use conocer that way. You are not saying you have met the person. You are saying you do not know the person’s identity. That calls for saber.

I Don’t Know Who That Is In Spanish In Real Conversations

Now let’s move from grammar to actual use. Most learners do not need ten textbook versions. They need three or four lines that fit real speech. Here are the ones that do the most work.

Casual Everyday Version

No sé quién es. This is the one you’ll use most. It sounds natural with friends, family, classmates, and coworkers. It is short, clear, and light.

Clearer Version When You Need To Point Someone Out

No sé quién es esa persona. Use this when “who that is” needs to be spelled out. It works well with photos, crowds, and social media posts where several faces may appear at once.

Polite Version In A Formal Setting

No estoy seguro de quién es. This one softens the line a bit. It can sound more tactful in work settings or when you do not want to sound blunt. A woman may say segura instead of seguro.

More Direct Version With A Name Or Description

No sé quién es ese señor. / No sé quién es esa chica. These work when the person is visible and you want to point them out in a natural way. Choose nouns with care, since tone matters. Persona stays neutral and safe.

What You Mean	Spanish Phrase	How It Sounds
I don’t know who that is	No sé quién es.	Most natural in daily speech
I don’t know who that person is	No sé quién es esa persona.	Clearer when context is weak
I’m not sure who that is	No estoy seguro de quién es.	Softer and more polite
I have no idea who that is	No tengo idea de quién es.	More emphatic, still natural
I don’t know who he is	No sé quién es él.	Used for stress or contrast
I don’t know who she is	No sé quién es ella.	Used for stress or contrast
I don’t know that guy	No conozco a ese hombre.	Changes meaning to familiarity
I don’t know his name	No sé cómo se llama.	Best when the issue is the name

What Changes The Tone

Small shifts can change the feel of the sentence. That matters more than many learners expect. Spanish has several ways to point to a person, and some sound warmer than others.

“Esa Persona” Sounds Neutral

If you want the safest add-on, use esa persona. It stays neutral, clear, and polite. It works in nearly any setting and does not draw extra attitude into the line.

“Ese” And “Esa” Can Sound Sharper

Spanish demonstratives like ese, esa, and eso do a lot of work. The RAE section on demonstratives explains how they function. In speech, a phrase like la chica esa can sound a bit dismissive depending on tone, region, and context. That does not mean it is always rude. It just carries more flavor than the plain, neutral esa persona.

If you are still building confidence, stick with the neutral choice first. You can always get more idiomatic later.

Pronouns Add Emphasis

Spanish often drops subject pronouns, so adding él or ella puts extra stress on the person. That can work if someone asks about one person among several. If no contrast is needed, the shorter version still wins.

Common Mistakes That Make The Phrase Sound Off

Most errors here come from direct translation. English and Spanish line up in parts, though they do not mirror each other fully. If you copy the English frame too closely, the sentence starts to wobble.

Less Natural Or Wrong	Better Spanish	Why
No conozco quién es	No sé quién es	Saber fits unknown identity
No sé quién es eso	No sé qué es eso / No sé quién es	Eso points to a thing, not a person
No sé quién es esa	No sé quién es ella / esa persona	Needs clearer person reference
No sé quien es	No sé quién es	Quién needs the accent mark
No sé quién está	No sé quién es	Ser marks identity here

Pick The Right Version For The Situation

The best translation depends on what you actually mean. Are you missing the name? The identity? Or do you mean that you have never met the person? Those are not the same thing in Spanish.

If You Mean You Do Not Know The Person’s Identity

Say No sé quién es. This is the broad, natural answer. It fits most cases where someone asks “Who’s that?” and you have no clue.

If You Mean You Have Never Met Them

Say No lo conozco or No la conozco. That means “I don’t know him” or “I don’t know her” in the sense of not being acquainted. It is a different idea from not knowing who the person is.

If You Only Mean You Do Not Know The Name

Say No sé cómo se llama. That line is tighter when the face is familiar but the name is missing. It saves you from sounding vague.

If You Want A Softer Tone

Use No estoy seguro de quién es. This works well when you want a little distance or when you think you might know the person but are not certain.

How It Sounds In Context

Context does half the work. Here’s how these lines play out in normal exchanges.

At a party:
—¿Quién es el chico de la chaqueta azul?
—No sé quién es.

Looking at a group photo:
—¿Y esa persona al lado de Marta?
—No sé quién es esa persona.

At work:
—¿Conoces al nuevo director?
—No estoy seguro de quién es.

Talking about a familiar face with an unknown name:
—Lo he visto antes, pero no sé cómo se llama.

Read those aloud and you can hear the difference. The short version feels loose and everyday. The longer versions narrow the meaning or soften the tone.

A Simple Rule That Keeps You Out Of Trouble

When you want to say “I don’t know who that is,” start with No sé quién es. If you need more clarity, add esa persona. If you mean “I don’t know him” in the sense of not being acquainted, switch to conocer. If you only lack the name, use No sé cómo se llama.

That one rule covers most real-life moments. It also keeps you away from stiff, word-for-word translations that sound like a dictionary was doing the talking.

So if you freeze the next time someone asks about a stranger in a photo or a person across the room, go with the line native speakers reach for most: No sé quién es.