Mi esperas, ke morgaŭ la aero estos klara, la elektro denove funkcios bone, kaj neniu plu devos krii pro la problemo.

Ke introduces a subordinate clause, like English that in I hope that....

So:

• Mi esperas = I hope
• ke morgaŭ... = that tomorrow...

In English, that is often optional, but in Esperanto ke is normally used when a full clause follows a verb like esperi, scii, diri, pensi, and so on.

In Esperanto, each finite verb shows its own tense with its ending.

• -os = future
• -as = present
• -is = past

Here the sentence contains three linked ideas:

• la aero estos klara
• la elektro denove funkcios bone
• neniu plu devos krii

Each one has its own verb, so each verb gets the future ending -os.

English can sometimes feel like it uses one future idea across a whole sentence, but Esperanto marks tense directly on each verb.

Because klara is an adjective describing the noun aero.

• klara = clear, as an adjective
• klare = clearly, as an adverb

In la aero estos klara, the word after estos is a predicate adjective: it describes what the air will be.

Compare:

• La aero estas klara. = The air is clear.
• La aero moviĝas klare. = The air moves clearly.
  This second one would be odd in meaning, but it shows how klare would work grammatically.

So here klara is correct because it describes aero, not the verb.

Because devi means to have to / must, and it is followed by an infinitive.

• devi = to have to
• krii = to shout / cry out

So:

• devos krii = will have to shout

This is very similar to English:

• I must go
• She has to wait
• They will have to shout

The tense goes on the modal verb:

• devas krii = has to shout
• devis krii = had to shout
• devos krii = will have to shout

The infinitive krii stays in the basic -i form.

Neniu means nobody / no one, and it normally takes a singular verb.

So:

• neniu devos = nobody will have to

Even though it refers to zero people, grammatically it behaves like singular no one in English.

Also note the difference between these correlatives:

• neniu = nobody / no one
• nenio = nothing

So neniu plu devos krii means no one will have to shout anymore, not nothing will have to shout.

They are similar in English translation sometimes, but they are not the same.

• denove = again
• plu = any longer, anymore, further

In this sentence:

• la elektro denove funkcios bone = the electricity will work well again
• neniu plu devos krii = nobody will have to shout anymore

So denove means something returns to a previous state, while plu means something continues no further or is no longer necessary.

They are not interchangeable here.

La is the definite article, meaning the.

Here, the speaker is not talking about air or electricity in general. They mean the specific air and the specific electricity in the situation being discussed:

• la aero = the air
• la elektro = the electricity / the power

Esperanto uses la when the thing is specific, known, or understood from context, much like English.

Here elektro means electricity or, in everyday context, the electrical power supply.

So la elektro denove funkcios bone is a natural way to say that the power will work properly again.

Depending on context, you may also see words like:

• kurento = current
• elektra kurento = electric current

But for ordinary situations such as outages or broken power service, la elektro is very natural.

Pro means because of / due to, and it is a preposition followed by a noun phrase.

• pro la problemo = because of the problem

By contrast, ĉar introduces a full clause:

• ĉar estis problemo = because there was a problem

So:

• pro + noun
• ĉar + clause

That is why pro la problemo works well here: it is short and directly followed by a noun phrase.

Yes. Esperanto word order is fairly flexible.

For example, these are all possible:

• Morgaŭ la aero estos klara.
• La aero morgaŭ estos klara.
• La aero estos klara morgaŭ.

And with bone:

• la elektro denove funkcios bone
• la elektro bone funkcios denove
• la elektro denove bone funkcios

These versions can sound slightly different in emphasis, but they are all grammatically possible.

In general, adverbs are often placed near the word or idea they modify, but Esperanto is less rigid than English about this.

Yes. Krii is correct.

Some Esperanto roots end in an i sound, and when the infinitive ending -i is added, you get ii in writing.

So:

• krii = to shout / cry out
• krias = shouts / is shouting
• krios = will shout

It is not a typo. Double vowels can happen in Esperanto, and both letters are pronounced.

In Esperanto punctuation, a subordinate clause introduced by ke is commonly separated by a comma.

So:

• Mi esperas, ke...

This is standard and very normal in written Esperanto.

You will often see the same pattern with other conjunctions introducing subordinate clauses, especially when the sentence becomes longer.