Espero que la sopa no quedi massa salada avui.

Because esperar que followed by a clause of hope or expectation normally takes the subjunctive in Catalan.

• Espero que... = I hope that...
• So the next verb goes in the subjunctive: quedi
• queda would be the indicative, which would not fit this structure.

So:

• Espero que la sopa no quedi... = correct
• Espero que la sopa no queda... = not correct here

Here quedar does not mean just to stay or to remain in a literal location sense. In cooking and similar contexts, it often means:

• to turn out
• to end up being
• to come out

So que la sopa no quedi massa salada means something like:

• that the soup doesn’t turn out too salty
• that the soup doesn’t end up too salty

This is a very natural use of quedar in Catalan.

Because salada is an adjective agreeing with la sopa, and sopa is a feminine singular noun.

So the adjective must also be feminine singular:

• la sopa salada
• not la sopa salat

Compare:

• el peix salat = the salty fish
• la sopa salada = the salty soup

Massa means too or excessively, while molt means very or a lot.

So:

• massa salada = too salty
• molt salada = very salty

That is an important difference. In this sentence, the speaker is hoping the soup is not overly salty, so massa is the right word.

In Catalan, the negative particle no normally goes directly before the conjugated verb.

So:

• no quedi = doesn’t turn out / won’t be
• la sopa no quedi = the soup not turn out...

This is the normal word order for negation.

Because que introduces the subordinate clause: that the soup not be too salty today.

Catalan often uses verb + que + subjunctive after verbs expressing:

• hope
• desire
• fear
• doubt
• emotion

So:

• Espero que vingui. = I hope he/she comes.
• Espero que la sopa no quedi massa salada avui.

In English, that is sometimes omitted, but in Catalan que is normally required here.

Because after esperar que, Catalan uses the present subjunctive to talk about a present or future situation that is hoped for.

So quedi does not mean the soup is already salty now. It refers to the result the speaker is hoping for, probably when the soup is served or finished.

This is similar to:

• Espero que arribi aviat. = I hope he/she arrives soon.
• Espero que faci bon temps demà. = I hope the weather is good tomorrow.

Even though the meaning is future, the form is still the present subjunctive.

Yes, that is possible, but it is slightly different in nuance.

• quedi massa salada suggests turns out / ends up too salty
• sigui massa salada suggests is too salty

In a cooking context, quedar often sounds especially natural because it focuses on the final result of the dish. Ser is possible, but quedar is often the more idiomatic choice when talking about how food turns out.

Putting avui at the end is very natural in Catalan. It simply adds the time reference: today.

Catalan word order is fairly flexible, so you could also hear:

• Espero que avui la sopa no quedi massa salada.

But Espero que la sopa no quedi massa salada avui sounds perfectly normal and natural.

Placing avui at the end can make it feel like a final time-setting detail.

Because Catalan often uses the definite article when referring to a specific thing already understood from the context.

Here la sopa likely means:

• the soup we are making
• the soup we are having today

Using the article is very normal in Catalan. English sometimes leaves articles out more easily than Catalan does.

Because here the verb means to turn out / to end up being, which is simply quedar.

Quedar-se is a different form with other meanings, such as:

• to stay
• to remain
• to keep

Examples:

• Em quedo a casa. = I’m staying at home.
• La sopa queda bona. = The soup turns out good.

So in this sentence, the correct verb is quedar, not quedar-se.