Mañana quiero preparar la cena junto con mi hermana.

Because Spanish often puts time expressions near the start to set the scene. Mañana tells you when the action happens, so placing it first is very natural.

You could also say:

• Quiero preparar la cena mañana junto con mi hermana.

That is also correct, but starting with mañana gives it a slightly more natural flow in many contexts.

It can mean both.

• mañana = tomorrow
• la mañana = the morning

In this sentence, because there is no article and it fits the context of time, mañana means tomorrow.

Compare:

• Mañana quiero preparar la cena. = Tomorrow I want to prepare dinner.
• Por la mañana quiero preparar la cena. = In the morning I want to prepare dinner.

Spanish often uses a conjugated verb followed by an infinitive, just like English.

Here:

• quiero = I want
• preparar = to prepare

So quiero preparar literally works like I want to prepare.

This is a very common pattern:

• quiero comer = I want to eat
• quiero salir = I want to go out
• quiero estudiar = I want to study

Because quiero is the first-person singular form of querer in the present tense.

querer = to want

Present tense:

• yo quiero = I want
• tú quieres = you want
• él/ella quiere = he/she wants
• nosotros queremos = we want
• vosotros queréis = you all want
• ellos quieren = they want

Spanish usually drops the subject pronoun, so quiero already means I want without needing yo.

Because Spanish often leaves out subject pronouns when the verb already makes the subject clear.

• quiero already tells you the subject is I

So:

• Quiero preparar la cena = I want to prepare dinner

You could say Yo quiero preparar la cena if you want emphasis, contrast, or clarity, but it is not necessary in a neutral sentence.

Not exactly. Preparar means to prepare or to get ready, and it can be broader than cook.

So preparar la cena may include:

• cooking it
• organizing it
• setting things up
• getting everything ready

If you specifically want to emphasize cooking, you might say:

• Mañana quiero cocinar la cena junto con mi hermana.

But preparar la cena sounds very natural and common.

Spanish often uses the definite article more than English does, especially with meals and everyday nouns.

So la cena is the normal way to say dinner in this context.

Compare:

• Voy a preparar la cena. = I’m going to prepare dinner.
• La cena está lista. = Dinner is ready.

English often drops the article, but Spanish frequently keeps it.

Junto con means together with or along with.

In this sentence, it shows that the speaker wants to prepare dinner in the company of their sister.

It is very similar to:

• con mi hermana = with my sister

But junto con can sound a little more explicit about doing something together.

Yes, absolutely.

• Mañana quiero preparar la cena con mi hermana.
• Mañana quiero preparar la cena junto con mi hermana.

Both are correct.

The version with junto con emphasizes the idea of being side by side or doing it jointly. The version with just con is simpler and very common.

Because mi hermana is not the direct object here.

The personal a is used before a person who is the direct object of a verb:

• Veo a mi hermana. = I see my sister.

But in your sentence, mi hermana comes after junto con, so it is part of a prepositional phrase, not the direct object:

• junto con mi hermana = together with my sister

So no personal a is needed.

Both are possible, but they are used differently.

• mi hermana = the normal, neutral way to say my sister
• hermana mía = more emphatic, expressive, or literary

In everyday speech, mi hermana is the usual choice.

So this sentence sounds natural:

• Mañana quiero preparar la cena junto con mi hermana.

In Spanish, h is silent.

So hermana is pronounced roughly like er-MA-na.

A few pronunciation notes for this sentence in Spain Spanish:

• mañana: the ñ sounds like ny in canyon
• quiero: the quie sounds roughly like kye
• junto: the j is a strong throaty sound, not like English j
• cena: in most of Spain, the c before e sounds like th in thin

So in much of Spain, cena sounds roughly like THE-na.

The word order is flexible. Spanish allows some movement, especially with time expressions and prepositional phrases.

These are all possible:

• Mañana quiero preparar la cena junto con mi hermana.
• Quiero preparar la cena mañana junto con mi hermana.
• Junto con mi hermana, mañana quiero preparar la cena.

The original version is natural and clear. Changes in order usually affect emphasis more than basic meaning.

Usually it suggests that you and your sister will prepare dinner together, so the natural reading is that she is involved in the action.

Because of junto con, the sentence leans toward shared participation, not just physical presence.

If you only wanted to say she would be nearby, you would probably phrase it differently.

Yes. Hacer la cena is also common and natural.

Compare:

• preparar la cena = prepare dinner
• hacer la cena = make dinner

Both work, but preparar can sound a bit more like getting dinner ready, while hacer is a very general everyday verb.

So all of these are fine:

• Mañana quiero preparar la cena junto con mi hermana.
• Mañana quiero hacer la cena junto con mi hermana.

Yes. Quiero is present tense, but that is normal.

The sentence means that right now, you have the desire or intention to do something tomorrow.

So the time reference works like this:

• quiero = present feeling/intention
• mañana = future time of the action preparar

This is very natural in Spanish, just as in English: Tomorrow I want to prepare dinner with my sister.