El uniforme es cómodo, pero el cinturón me queda un poco apretado.

In Spanish, ser is generally used for more permanent or inherent characteristics, and estar for temporary states.

• El uniforme es cómodo = The uniform is (inherently) comfortable, by design or in general.
• El uniforme está cómodo would sound odd, because objects usually don’t “feel comfortable” in a temporary way.

You can use estar cómodo for people:

• Estoy cómodo = I am comfortable (right now).

For clothes, Latin American Spanish very strongly prefers ser for this kind of description: es cómodo.

Adjectives in Spanish agree in gender and number with the noun they describe.

• Noun: el uniforme → masculine, singular.
• Adjective: cómodo → masculine, singular to match uniforme.

If the noun were feminine or plural, the adjective would change:

• La camisa es cómoda.
• Los uniformes son cómodos.
• Las camisas son cómodas.

The verb quedar with an indirect object pronoun (me, te, le, etc.) is a standard way to talk about how clothes fit someone:

• El cinturón me queda un poco apretado.
  • el cinturón = subject (the thing doing the “fitting”)
  • me = “to me / on me”
  • queda = “fits / ends up”
  • un poco apretado = “a bit tight”

So structurally it’s like:
[The belt] [to me] [fits] [a bit tight].

Other examples:

• Estos zapatos me quedan grandes. = These shoes are too big on me.
• La chaqueta te queda perfecta. = The jacket fits you perfectly.

You can say it and it will be understood, but it sounds less natural than me queda un poco apretado.

For clothing fit, Spanish speakers normally use:

• quedar: El cinturón me queda apretado.
• or apretar: El cinturón me aprieta.

Ser + apretado sounds more like “it is a tight object in general,” not specifically “it’s tight on me.” So in everyday speech, me queda apretado is the idiomatic choice.

Again, agreement: apretado is describing el cinturón, which is masculine singular.

• el cinturón → masculine singular → apretado
• If it were feminine: la falda me queda un poco apretada.

The adjective does not agree with me; it agrees with the noun (cinturón).

They look similar but they mean almost opposite things:

• un poco apretado = a little bit tight (it’s somewhat tight)
• poco apretado = not very tight / hardly tight (almost loose)

In your sentence:

• me queda un poco apretado = it’s slightly tight on me.

If you said:

• me queda poco apretado, you’d be saying it’s not very tight, maybe looser than you’d like.

In Spanish, countable singular nouns almost always need an article (el, la, un, una) unless there is a special reason not to use one.

Here we’re talking about a specific uniform and belt, so we use the definite article:

• El uniforme es cómodo.
• El cinturón me queda un poco apretado.

Saying “Uniforme es cómodo” sounds wrong in normal Spanish. You might only see nouns without articles in special contexts (headlines, labels, telegram style), e.g. “Uniforme: cómodo y práctico” in an advertisement.

Both pero and sino can be translated as “but,” but they are used differently:

• pero = but, to add a contrast:

  • El uniforme es cómodo, pero el cinturón me queda un poco apretado.
    The first part is true; the second adds a contrasting fact.

• sino = but rather, but instead, used to correct a negation:

  • No es incómodo, sino un poco apretado.
    It’s not uncomfortable, but rather a bit tight.

In your sentence, nothing is being negated, so pero is the correct conjunction.

With a conjugated verb like queda, the clitic pronoun (me, te, le, etc.) normally goes before the verb:

• El cinturón me queda un poco apretado. ✓

You cannot say:

• El cinturón queda me un poco apretado. ✗
• El cinturón un poco me queda apretado. ✗

If you used an infinitive or gerund, you could attach the pronoun:

• El cinturón va a quedarme apretado.
• El cinturón está quedándome apretado.

You can add emphasis with a mí before it:

• A mí, el cinturón me queda un poco apretado.

Quedar has several very common meanings:

1. To fit / suit (clothes, styles):

   • Este vestido te queda bien.

2. To be left / remain:

   • Sólo quedan dos asientos. = Only two seats remain / are left.

3. To end up / turn out:

   • La sopa quedó muy rica. = The soup turned out very tasty.

4. To be located (informally):

   • ¿Dónde queda el baño? = Where is the bathroom (located)?

5. To arrange to meet:

   • Quedamos a las 8. = We arranged to meet at 8.

In your sentence, it’s in the “fit” sense.

In Latin American Spanish, cinturón is the most standard word for a belt you wear around your waist with pants.

correa can mean:

• a strap (bag strap, dog leash, etc.)
• a watch strap: la correa del reloj

In some regions, people may also say correa for a pants belt, but cinturón is widely understood everywhere in Latin America and is the safest choice in neutral Spanish.

Yes, you can say:

• El cinturón me aprieta un poco.

Both are natural, but the focus is slightly different:

• me queda un poco apretado → describes the fit of the belt (how it is on your body).
• me aprieta un poco → emphasizes the feeling of pressure, that it is squeezing you.

In everyday conversation, both are very common ways to complain that something is a bit too tight.

Spanish accent marks show where the stress falls when it doesn’t follow the normal rules.

General rule:

• Words ending in a vowel, n, or s are normally stressed on the second-to-last syllable.

cómodo ends in a vowel (o), so by the rule we would expect stress on mo: co-MO-do.
But the correct pronunciation is CÓ-mo-do, with stress on the first syllable.

To show this irregular stress, Spanish writes an accent: cómodo.

So the accent mark tells you:

• Don’t say co-MO-do.
• Say CÓ-mo-do.