No uses la freidora sin mirar la temperatura primero.

Because this is a negative command: Don’t use...

In Spanish, negative commands for tú use the present subjunctive, not the normal present tense.

• usas = you use
• no uses = don’t use

So:

• Usas la freidora. = You use the fryer.
• No uses la freidora. = Don’t use the fryer.

No uses is the informal singular command, used with tú.

So this sentence is talking to one person in an informal way.

Related forms:

• tú → No uses
• usted → No use
• vosotros (common in Spain) → No uséis
• ustedes → No usen

In Spain, if you were speaking to several people informally, you would usually say:

• No uséis la freidora sin mirar la temperatura primero.

Because Spanish usually leaves subject pronouns out when they are not needed.

The verb form uses already shows that the sentence is directed at tú.

So:

• No uses la freidora...
• Tú no uses la freidora...

Both are possible, but the first is more natural in most situations. Adding tú can sound emphatic.

Spanish normally uses the definite article much more often than English.

So la freidora means the fryer, and in this kind of instruction it sounds natural because both speaker and listener understand which fryer is meant, or the phrase refers to the appliance in general.

In English, instructions often drop the more easily, but Spanish usually keeps it.

Freidora means fryer or deep fryer.

In Spain:

• freidora usually means a fryer in general
• freidora de aire specifically means air fryer

So by itself, la freidora will usually be understood as a regular fryer unless the context suggests otherwise.

After sin (without), Spanish often uses an infinitive when the subject is the same as in the main clause.

So:

• sin mirar = without looking / without checking

This is very normal Spanish.

The structure is:

• sin + infinitive

Examples:

• sin hablar = without speaking
• sin pensar = without thinking
• sin mirar la temperatura = without checking the temperature

Literally, mirar means to look at, but in many contexts it can also mean to check or to look to see.

So here, mirar la temperatura naturally means something like:

• check the temperature
• look at the temperature

A few similar verbs are:

• mirar = look at / check
• ver = see
• comprobar = check / verify
• revisar = check / inspect

In a safety instruction like this, mirar sounds very natural and everyday.

Spanish often uses the definite article where English might use a possessive like its or the.

So instead of saying its temperature, Spanish often just says:

• la temperatura

Because the context already makes it clear that we mean the fryer’s temperature.

This is very common in Spanish, especially with body parts, objects, and things closely connected to the situation.

Primero means first.

It tells you the order of actions:

1. check the temperature
2. then use the fryer

So the sentence means you should check the temperature first before using the fryer.

Yes, it can move.

In your sentence:

• No uses la freidora sin mirar la temperatura primero.

Primero at the end sounds natural and clearly emphasizes the sequence.

You could also say:

• No uses la freidora sin mirar primero la temperatura.

That is also correct.

Both are natural. The difference is mostly about rhythm and emphasis, not basic meaning.

Yes, but the structure changes a little.

Primero works naturally in the original sentence:

• No uses la freidora sin mirar la temperatura primero.

If you want to use antes, a very common option is:

• No uses la freidora sin mirar antes la temperatura.

That also means Don’t use the fryer without checking the temperature first.

So both primero and antes can work here.

Yes. A very common alternative would be:

• Mira la temperatura antes de usar la freidora.

That means:

• Check the temperature before using the fryer.

This version sounds a bit more like a straightforward instruction, while the original is framed as a warning:

• Don’t use the fryer without checking the temperature first.

Both are natural; they just focus on the instruction differently.

In Spain, the usual informal plural is vosotros, so the negative command would be:

• No uséis la freidora sin mirar la temperatura primero.

That is the plural version of the same sentence for a group you address informally.

If you wanted a formal plural, you would say:

• No usen la freidora sin mirar la temperatura primero.