‘Su’ vs ‘tu’

Along with ‘dos cervezas, por favor’ and ‘qué será, será’, you must have heard the phrase, ‘mi casa es su casa’. But if the latter means ‘my house is your house’, then why isn’t it ‘mi casa es tu casa’?

Well, that, my friends, is the real question (and not that other one from Shakespeare).

In short – ‘tu’ means ‘your’ and refers to the fact that something / someone belongs to the person you’re talking to; ‘su’ is for (almost) everyone else: ‘his’, ‘her’, ‘their’ and ‘its’.


As alluded to above, ‘tu’= ‘your’. 

An example –

Vamos a tu casa.

Let’s go to your house.

Whoa there, Tiger. Why don’t we have dinner first?

But back to ‘su’ (no, not my annoying neighbor, Sue). ‘Su’ can also mean ‘your’ in two kinds of situations: formal (i.e., the ‘usted’ form) and when you’re talking to multiple people.

And if that wasn’t enough, ‘su’ can also mean: ‘his’ / ‘her’ /‘its’ / ‘their’.


So, when someone says something like, “Su casa es muy linda”, how (on earth!) do you work out whose house it actually is?

Oh no, I hear you moan … but don’t despair, because once you’ve read this article, you’ll be a trainee expert on the topic (psst, spoiler alert: it’s all about the CONTEXT and then it’s easy-peasy lemon-squeezy.) 

When to use ‘tu’ 

Tu’ is the Spanish equivalent of ‘your’, for when we’re talking to one person who we know quite well – a friend, a family member, a wife, a husband, a pet, etc.

Two easy examples –

Ponte cómodo, estás en tu casa

Relax, you’re at (your) home.

Tu novio me llamó hace rato – cuidado con él, eh!

Your boyfriend called me earlier – be careful with him!

I can almost hear your (tu) sigh of relief. Whoa there, not so fast

Tu’ or ‘

You might sometimes confuse ‘tu’with ‘’. An easy mistake to make and even easier to rectify!

As you can see, one has a sombrero (yep, I’m talking about ‘’), and this ‘’ means ‘you’, NOT your’.

’ is what we call a subject pronoun.

Wait, what’s a subject?

Well, it’s what carries out the verb – the agent, if you will.

For example, in the sentences ‘You speak Spanish’ and ‘She speaks Spanish’ – ‘you’ and ‘she’ are agents that do the speaking. 

A couple of examples to illustrate the difference between ‘tu’ and ‘’ –

¿Y tú cómo estás? 

And how are you?

¡Hazlo tú!

Do it yourself!

You see? Not to be confused with its hatless twin, Mr. Tu. 

¿Olvidaste tu sombrero, Señor Tu?

Did you forget your hat, Mr. Tu?

Quítate tu sombrero, Señor Tu – así se muestra el respeto.  

Take off your hat, Mr. Tu – it’s a sign of respect.

I mean, it’s much a ‘tu’ about nothing if you ask me, but when you’re reading and writing, the distinction between ‘tu’ and ‘’ es muy importante, amigos.

When to use ‘su’

As we mentioned earlier: there are A LOT of situations in which you can use ‘su’; but believe me, it’s simpler than you’d think.

Like those who work in real estate always talk about “Location, Location, Location, we linguists are similarly obsessed with “Context, Context, Context”, because you’re gonna need to look at the context to know who exactly ‘su’ refers to. 

Let’s get down to business*!

*linguistics not real estate …

‘Su’ for ‘you’ (usted)

Generally, we use the “formal you” (i.e., ‘usted’) when interacting with people in formal (well, duh!) situations.

For example, someone we don’t know, someone we consider a senior citizen, ordering in a restaurant and even *sometimes* when reprimanding a pet (weird, I know). 

For example –

¿Le gustaría aderezo para su ensalada, señora?

Would you like some dressing for your salad, Madam?

Espere, se le olvidó su abrigo.

Wait, you forgot your coat, Sir.

Su’ for ‘you (plural)

In English there’s no real language authority like the RAE in Spanish, and there’s a lot of variety, but to address a group of people we generally use ‘you guys’, ‘y’all’, ‘you lot’ and even ‘yous’ (in the North of England). 

So that’s what I mean when I say ‘you’ (plural). 

An example –

A host greets his or her guests

Mi casa es su casa. (that ol’ classic) 

My house is your house.

Su’ for ‘her

When we refer to something belonging to someone who identifies as female, we use ‘su’. 

Pues, ¿dónde está? Vi su coche llegar.

Well, where is she? I saw her car pulling up.

Su’ for ‘his

Likewise, when we refer to something belonging to someone who identifies as male, we use ‘su’. 

Su camisa está bien padre.

His shirt is awesome.

Su’ for ‘their

To refer to something belonging to two or more people, or to someone you don’t know the gender of, we use ‘su’.

¿Ya viste su casa? ¡Está enorme!

Have you already seen their house? It’s huge!

Su’ for ‘its

To refer to something belonging to an animal or a thing we – you guessed it – also use ‘su’.

El águila es hermosa pero su pico es muy fuerte y puede perforar hueso.

The eagle is beautiful, but its beak is very strong and can pierce bone.

I hope you can see from the above examples that, if you pay attention to the context, knowing who exactly ‘su’ refers to is “pan comido” – a piece of cake.

Tus’ and ‘sus

You’re probably wondering why you sometimes see ‘tus’ and sus

Well, we use them both with PLURAL NOUNS – a noun being an idea, thing, or person. 

Compare the following two examples –

TU silla es buena.

Your chair is good.

TUS sillas son buenas.

Your chairs are good.

And another comparison with ‘su’ –

SU coche es muy bueno. 

Their car is very good.

SUS hijos son chicos buenos*.

Their children are good kids.

Erika’s note – make sure your adjectives also agree in number with the noun they’re modifying. Mosey on down to our article on ‘buenos’ and ‘buenas’ if you´d like to know more!

Remember: if there’s more than one of something, just add an ‘s’.

Apart from that, we use the ‘tus’ and ‘sus’of the world in the exact same way we would ‘tu’and ‘su’.

Final thoughts

So, there you have it. 

As a student of Spanish, you should consider yourself pretty lucky because you only have to use ‘mi’, ‘tu’ and ‘su’ (and ‘nuestro’for ‘our’) when talking about possessions. Imagine learning English … ‘my’, ‘you’, ‘our’, ‘his’, ‘her’, ‘their’, ‘its’ … no thanks!

Oh, and since we talked so much about this and that today, why not check out our article on eso’ vs ‘aquello? Confusingly, they can both mean ‘that’ …

Time for a beer? All right – where? Tu casa o su casa? 😉

Rupert's lived in Mexico for nearly a decade and has been working as a Spanish teacher for even longer (over 10 years now, wow!). He specializes in simple (yet effective) explanations and is a veritable grammar-whizz.

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