Guarda el pan en el congelador si no vas a comerlo hoy.

Yes. Guarda is the tú imperative of guardar, so it means store / keep / put away when speaking to one person informally.

So:

• Guarda el pan... = Store the bread... / Put the bread away...

If you were speaking more formally to one person, you would say:

• Guarde el pan...

And in Spain, to more than one person informally:

• Guardad el pan...

This is a very common question because guardar can look like the English word guard, but in everyday Spanish it often means:

• to keep
• to store
• to put away
• to save

So in this sentence, guarda el pan en el congelador means put the bread in the freezer / store the bread in the freezer, not protect the bread.

Spanish often uses the definite article more than English does.

Here, el pan refers to the bread in a general practical sense: the bread we are talking about, the bread you have. In English, we might just say bread, but Spanish often prefers the article.

So:

• Guarda el pan... = Put the bread away...

Using el here sounds natural and normal.

Congelador means freezer, not just any cold appliance.

Useful contrast:

• nevera / frigorífico = fridge
• congelador = freezer

So this sentence specifically says to put the bread in the freezer, not the fridge.

Ir a + infinitive is a very common way to talk about what someone is going to do.

So:

• vas a comerlo = you are going to eat it

This sounds very natural in Spanish, just like going to eat it in English.

You could sometimes express the idea differently, but here si no vas a comerlo hoy is a very natural way to say if you are not going to eat it today.

Because the structure is:

• ir + a + infinitive

So:

• vas = you go / you are going
• a comer = to eat

Together:

• vas a comer = you are going to eat

This is a fixed future-like structure in Spanish.

Because when a direct object pronoun goes with an infinitive, it can be attached to the end.

Here:

• comer = to eat
• lo = it

So:

• comerlo = to eat it

This is completely normal Spanish.

With ir a + infinitive, there are usually two natural options:

• no vas a comerlo hoy
• no lo vas a comer hoy

Both are correct.

Yes. That is also correct and very natural.

Both of these work:

• si no vas a comerlo hoy
• si no lo vas a comer hoy

The meaning is the same: if you are not going to eat it today.

Learners often prefer lo vas a comer at first because it may feel easier to process, but vas a comerlo is equally standard.

Because pan is the direct object of comer.

You eat the bread, so the bread is the thing directly affected by the verb. That means Spanish uses a direct object pronoun:

• lo for masculine singular
• la for feminine singular

Since pan is masculine singular:

• el pan → lo

So:

• comer el pan → comerlo

Not comerle, because le is normally an indirect object pronoun.

Because this sentence is talking about a real, possible situation, not something hypothetical or doubtful.

• Si no vas a comerlo hoy... = If you’re not going to eat it today...

After si meaning if, Spanish normally uses the present indicative or another normal indicative form for real conditions like this.

So this is the expected grammar.

Spanish word order is flexible, and hoy often goes at the end very naturally.

• si no vas a comerlo hoy

This is the most neutral order here.

You could also hear:

• si hoy no vas a comerlo
• si no lo vas a comer hoy

But the original version sounds smooth and natural.

Yes, but then the command form would change because negative imperatives use the subjunctive form.

For tú:

• Guarda el pan... = Put the bread away...
• No guardes el pan... = Don’t put the bread away...

So the positive and negative command forms are different.

For one person formally:

• Guarde el pan en el congelador si no va a comerlo hoy.

For more than one person formally:

• Guarden el pan en el congelador si no van a comerlo hoy.

In Spain, for more than one person informally, you would usually say:

• Guardad el pan en el congelador si no vais a comerlo hoy.

It is two words here:

• si = if
• no = not

So:

• si no vas a comerlo hoy = if you are not going to eat it today

Do not confuse this with sino as one word, which has a different meaning, often something like but rather / except.

Grammatically, that is close, but save is not the most natural English translation here. A more natural English version would be:

• Put the bread in the freezer if you’re not going to eat it today.
• Store the bread in the freezer if you’re not going to eat it today.

That is because guardar in this context is about storing/putting away, not saving in the emotional or dramatic sense.

In context, it usually means the bread you have. Spanish el pan can refer to a specific loaf, some bread already mentioned, or bread understood from the situation.

So it does not have to mean just one exact piece. It is simply the bread being talked about.

Yes. It sounds natural in Spain.

A Spaniard might also say slight variations such as:

• Mete el pan en el congelador si no vas a comerlo hoy.
• Guarda el pan en el congelador si no te lo vas a comer hoy.

But the original sentence is perfectly normal and idiomatic.