If you’re confused about the difference between tu and su in Spanish, you’re not alone. These two small words cause big hesitation for English speakers because they both translate to “your” in different situations. Let’s break it down clearly so you know exactly when to use each one.

Quick Answer

“Tu” means “your” when speaking informally to one person.
“Su” means “your” (formal), “his,” “her,” or “their.”

If you’re talking to a friend, use tu. If you’re speaking formally or referring to someone else’s possession, use su.

Why “Tu vs Su” Confuses English Speakers

In English, we only have one word: “your.” It doesn’t change based on formality.

Spanish does.

Spanish also uses the same word (su) for:

• his
• her
• their
• your (formal)
• your (plural in Latin America)

That’s where the real confusion begins.

When you hear:

• su casa

It could mean:

• his house
• her house
• their house
• your house (formal)

Context matters. And that makes English speakers uncomfortable because we’re used to more precision in possessives.

The Practical Rule (The Fast Decision Guide)

Ask yourself two questions:

1.- Are you talking directly to someone?

If yes:

• Talking to a friend, child, sibling → tu
• Talking to a boss, stranger, older person (formal) → su

2.- Are you talking about someone else?

If yes → su

That’s it.

If it’s not informal “you,” it’s almost always su.

Real Examples You’ll Actually Use

Informal (tu)

• ¿Dónde está tu teléfono?
  Where is your phone? (talking to a friend)
• Me gusta tu idea.
  I like your idea.
• Tu hermano es muy simpático.
  Your brother is very nice.

Formal (su = your formal)

• Señor García, su oficina está lista.
  Mr. García, your office is ready.
• ¿Es este su asiento?
  Is this your seat? (formal)

Third Person (su = his/her/their)

• Juan perdió su cartera.
  Juan lost his wallet.
• María está con su mamá.
  María is with her mom.
• Los estudiantes trajeron su tarea.
  The students brought their homework.

Notice something important: su does not change based on gender.

It matches the thing owned, not the owner.

• su casa (house is feminine)
• su libro (book is masculine)

The Hidden Detail Most Learners Miss

Tu changes to “tus” in plural.
Su changes to “sus” in plural.

• tu amigo → tus amigos
• su problema → sus problemas

The plural is about the object, not the person.

Common Mistakes (And Why They Happen)

Using “su” for everything

Many learners overuse su because it feels safer. That makes you sound distant or overly formal with friends.

If you’re talking to a close friend and you say:

• su casa

It sounds like you’re creating distance.

Confusing “tú” and “tu”

These are different words:

• tú (with accent) = you
• tu (no accent) = your

Example:

• Tú tienes tu libro.
  You have your book.

The accent matters.

Thinking “su” tells you who owns something

It doesn’t.

If clarity is needed, Spanish speakers often say:

• la casa de él (his house)
• la casa de ella (her house)
• la casa de ellos (their house)

Spanish relies heavily on context.

A Smarter Way to Think About It

Don’t think in terms of “your.”

Think in terms of:

• informal you → tu
• everything else → su

It’s simpler and more accurate.

FAQs About Tu vs Su in Spanish

1. Is “su” formal or plural?

It can be both.
“Su” is used for formal “you” (usted), plural “you” in Latin America (ustedes), and for his/her/their.

Context decides the meaning.

2. Does “su” mean his or her?

Yes. It can mean his, her, their, or your (formal). Spanish doesn’t change the possessive based on the owner’s gender.

3. When should I use “tu” instead of “su”?

Use “tu” when speaking informally to one person you know well (friend, sibling, child).

If you’re unsure whether the situation is formal, “su” is safer — but don’t overuse it with friends.

4. What is the plural of “tu” and “su”?

• tu → tus
• su → sus

They change based on the number of items owned.

5. Is “tú” the same as “tu”?

No.
“Tú” (with accent) means “you.”
“Tu” (no accent) means “your.”

6. Why doesn’t Spanish separate his and her?

Spanish possessives agree with the object owned, not the owner. Gender of the owner is usually clear from context.

7. How do I clarify if “su” is confusing?

Add clarification:

• su libro de ella
• su casa de Juan

Or more naturally:

• el libro de ella
• la casa de Juan

8. Do people in Spain use “su” the same way?

Yes, but Spain also uses vosotros for informal plural “you,” which changes possessives in some contexts. In Latin America, “ustedes” uses “su.”

Final Takeaway

If you’re hesitating between tu vs su in Spanish, stop translating directly from English.

Instead, decide:

• Am I speaking informally to one person? → tu
• Anything else? → su

Simple. Clear. Correct.

And once you start noticing it in real conversations, the confusion disappears fast.

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You can also read the blog What Is the Difference Between Tu vs. Su in Spanish for more on this topic.

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