Si llueve, no uses sandalias y lleva zapatos cerrados.

In this sentence, “si llueve” uses the present indicative (llueve) because it talks about a real, possible condition in the future:

• Si llueve, no uses sandalias…
  = If it rains (which is a real possibility)...

You use the subjunctive (llueva) in different types of sentences, for example with cuando or in more hypothetical structures, but in standard modern Spanish:

• After si
  • a real/likely condition, you generally use indicative:
    
    • Si llueve, me quedo en casa. – If it rains, I’ll stay home.

You do see subjunctive in more theoretical/less likely structures:

• Aunque llueva, iré. – Even if it rains, I’ll go.
• Si lloviera, no saldríamos. – If it rained, we wouldn’t go out. (hypothetical)

But “si llueva” is not standard in this kind of everyday conditional sentence.

Because this is a command (an instruction), not a simple statement.

In Spanish, for negative commands with tú, you use the present subjunctive:

• Verb usar:
  • (tú) usa – wear/use (affirmative command)
  • (tú) no uses – don’t wear/use (negative command)

So:

• ✅ No uses sandalias. – Don’t wear sandals.
• ❌ No usas sandalias. (This sounds like You don’t wear sandals as a statement, not a command.)

The structure is:

• No + [tú form of present subjunctive] → negative command
  
  • No uses, no comas, no hables, no salgas, etc.

Yes, both are addressing tú (informal “you”), but Spanish forms affirmative and negative commands differently:

For tú:

• Affirmative command → 3rd person singular of present indicative
  
  • usar → usa
  • llevar → lleva
• Negative command → tú form of present subjunctive
  
  • usar → no uses
  • llevar → no lleves

So in your sentence:

• no uses sandalias → negative command
• lleva zapatos cerrados → affirmative command

That’s why one has -es and the other doesn’t. It’s the standard pattern, not an irregular verb issue.

The sentence is informal, addressing tú.

• Tú (informal, singular)
  
  • No uses sandalias y lleva zapatos cerrados.

For usted (formal, singular), commands use the subjunctive for both affirmative and negative:

• No use sandalias y lleve zapatos cerrados.

For ustedes (plural “you” in Latin America):

• No usen sandalias y lleven zapatos cerrados.

So in Latin America, addressing a group formally or informally, you’d typically say:

• Si llueve, no usen sandalias y lleven zapatos cerrados.

In voseo areas (e.g., Argentina, Uruguay, much of Central America), tú is often replaced by vos, and the commands change:

• vos affirmative: often stress on the last syllable, sometimes accent written.
• vos negative: uses subjunctive vos form, often similar to tú but with different stress.

Typical voseo version (varies slightly by region):

• Si llueve, no usés sandalias y llevá zapatos cerrados.

Here:

• no usés (negative vos command of usar)
• llevá (affirmative vos command of llevar)

In Spanish, subject pronouns are usually dropped because the verb ending already shows the person:

• uses → only fits tú in this context.
• lleva → in a command context, it’s clearly tú.

You can say:

• Si llueve, tú no uses sandalias y lleva zapatos cerrados.

…but adding tú usually:

• adds emphasis (you in particular), or
• can sound a bit more marked/insistent.

In a neutral instruction, the natural version is exactly what you have: without the pronoun.

Both usar and llevar can be used with clothing, but there are nuances:

• usar = to use / wear as a general usage:

  • Usa gafas. – He wears glasses.
  • No uses sandalias. – Don’t wear sandals.

• llevar = to carry / have on / wear:

  • Lleva un abrigo negro. – She’s wearing a black coat / She carries a black coat.

In this context:

• No uses sandalias sounds like “don’t use sandals as your footwear”
• You could also say No lleves sandalias, which is very natural too.

The sentence mixes them:

• no uses sandalias (don’t use sandals)
• lleva zapatos cerrados (wear closed shoes)

This is normal and idiomatic; both verbs work with clothing/footwear.

Literally, “zapatos cerrados” = “closed shoes”.

In practice, it usually refers to:

• shoes that cover the whole foot (especially toes, and often heel too), e.g. sneakers, dress shoes, work shoes.

In many real-world contexts (schools, workplaces, safety rules), “zapatos cerrados” is effectively “closed-toe shoes”, i.e.:

• ✅ sneakers, loafers, work boots
• ❌ sandals, flip-flops, open-toe heels

If you want to be ultra-explicit about the toes, you might hear “zapatos cerrados de la punta”, but zapatos cerrados is usually enough.

Because adjectives in Spanish must agree in gender and number with the noun they describe.

• zapatos → masculine, plural
• cerrado → masculine, singular
• cerrados → masculine, plural

So you need cerrados:

• un zapato cerrado – one closed shoe
• zapatos cerrados – closed shoes
• una sandalia cerrada – a closed sandal
• sandalias cerradas – closed sandals

The -s at the end matches the plural noun.

In Spanish:

• si (no accent) = “if” (conditional particle)

  • Si llueve, no uses sandalias. – If it rains, don’t wear sandals.

• sí (with accent) = “yes”, or reflexive/emphatic “himself/herself/itself/etc.”

  • Sí, voy. – Yes, I’m going.
  • Lo hizo él mismo, él sí pudo. – He did it himself; he did manage to.

Your sentence is using si = if, so there is no accent.

You can say both; they’re both correct, but there’s a nuance:

• Si llueve, no uses sandalias…
  – If it rains (in general / at that time), don’t wear sandals.

• Si está lloviendo, no uses sandalias…
  – If it is raining (right then), don’t wear sandals.

In practice:

• Si llueve often sounds like a more general condition (looking ahead: if it rains at that time).
• Si está lloviendo focuses more on the action actually happening at that moment.

Both are natural; the original is slightly more general and common in instructions.

Yes. In Spanish, si-clauses (if-clauses) can go before or after the main clause without changing the basic meaning:

• Si llueve, no uses sandalias y lleva zapatos cerrados.
• No uses sandalias y lleva zapatos cerrados si llueve.

Both are natural.
Putting the si-clause first often feels a bit more “condition-focused,” but both orders are very common and correct.