La trankvileco de la nokto helpas min dormi pli bone.

Trankvileco means calmness, tranquility, or the quality of being calm.

• trankvila = calm, quiet, tranquil (an adjective)
• trankvilo = calm, peace, quietness
• trankvileco = calmness, tranquility, the abstract quality of being calm

In this sentence, la trankvileco de la nokto means the tranquility/calmness of the night.

A learner may also notice that both trankvilo and trankvileco can sometimes seem possible. In practice:

• trankvilo often feels a bit more like peace/calm
• trankvileco stresses the quality or state of being tranquil

So trankvileco is a natural way to express the tranquility of the night.

The suffix -eco forms an abstract noun meaning the quality/state of being ...

Examples:

• bela = beautiful → beleco = beauty
• granda = big → grandeco = size, greatness
• trankvila = calm → trankvileco = calmness, tranquility

So trankvileco is built like this:

• trankvil- = calm
• -ec- = quality/state
• -o = noun ending

This is a very common and useful Esperanto pattern.

De often means of.

So:

• la trankvileco de la nokto = the tranquility of the night

This is the normal way in Esperanto to show this kind of relationship.

Compare:

• la pordo de la domo = the door of the house
• la koloro de la ĉielo = the color of the sky
• la fino de la tago = the end of the day

English sometimes uses of, and sometimes uses a noun as an adjective, like night calmness. Esperanto usually uses de in a phrase like this.

Yes. La nokta trankvileco is also correct and means roughly the night-time tranquility or the night’s tranquility.

The difference is mostly stylistic:

• la trankvileco de la nokto = the tranquility of the night
• la nokta trankvileco = the nocturnal/night-time tranquility

Both are natural. The version with de is a little more direct and transparent for beginners.

Because both nouns are definite:

• la trankvileco = the tranquility
• la nokto = the night

Esperanto uses la much like English the. If both things are definite, both can take la.

So the phrase literally works like:

• the tranquility of the night

Compare:

• la libro de la instruisto = the book of the teacher
• la sono de la vento = the sound of the wind

After helpi, Esperanto commonly uses the direct object for the person being helped:

• helpi iun fari ion = to help someone do something

So:

• helpas min dormi = helps me sleep

This is a very common pattern.

Examples:

• Li helpis min kompreni. = He helped me understand.
• Ŝi helpas la infanojn lerni. = She helps the children learn.

Some learners expect al mi because English says help to me in some structures, but in Esperanto min is the standard form here.

Min is the accusative form of mi.

In this sentence, min is the direct object of helpas:

• La trankvileco ... helpas min ...
• The tranquility ... helps me ...

Esperanto marks direct objects with -n.

Compare:

• Mi vidas lin. = I see him.
• Ŝi aŭdas nin. = She hears us.
• Tio helpas min. = That helps me.

So min is there because me is the thing/person being helped.

Because it follows helpas in a structure like:

• helpi iun fari ion = to help someone do something

So:

• helpas min dormi = helps me sleep

The verb after helpi stays in the infinitive:

• Mi helpas vin labori. = I help you work.
• Tio helpis ŝin resaniĝi. = That helped her recover.

This is similar to English help someone do something.

Pli bone means better.

It is built from:

• bone = well
• pli = more

So literally:

• pli bone = more well = better

Examples:

• Mi fartas bone. = I feel well.
• Mi fartas pli bone. = I feel better.

In your sentence:

• dormi pli bone = sleep better

Because bone is an adverb, and here it modifies the verb dormi.

• bona = good (adjective, describes a noun)
• bone = well (adverb, describes a verb/adjective/adverb)

Since the sentence is about how someone sleeps, Esperanto uses the adverb:

• dormi bone = to sleep well
• dormi pli bone = to sleep better

Compare:

• bona dormo = a good sleep
• Mi dormas bone. = I sleep well.

Not explicitly. Just like English sleep better, Esperanto dormi pli bone can leave the comparison unstated.

It usually implies something like:

• better than usual
• better than before
• better than in noisier conditions

So the sentence does not need to say exactly better than what. The context supplies that.

Yes, to some extent. Esperanto word order is fairly flexible because grammar endings show the roles of words.

The neutral order here is:

• La trankvileco de la nokto helpas min dormi pli bone.

You could also say:

• La trankvileco de la nokto min helpas dormi pli bone.

But that sounds less neutral. The original version is the most natural for ordinary use.

Because min has -n, we still know it is the object even if the order changes. Still, beginners should usually prefer the more standard, clearer order.

A rough pronunciation guide is:

la trahn-kvee-LEH-tso de la NOK-to HEL-pahs meen DOR-mee plee BO-neh

A few helpful points:

• tr is pronounced clearly, not like English ch
• v is always like English v
• c in Esperanto sounds like ts
• e is always like eh
• o is always like oh
• stress is always on the second-to-last syllable

So:

• tran-kvi-LE-co
• NOK-to
• HEL-pas
• DOR-mi
• BO-ne

The structure is:

• La trankvileco de la nokto = subject
• helpas = verb
• min = direct object
• dormi pli bone = infinitive phrase explaining what I am helped to do

So the pattern is:

[Subject] + [verb] + [person helped] + [infinitive phrase]

More abstractly:

• The tranquility of the night
  • helps
    • me
      • sleep better

This is a very useful Esperanto sentence pattern to recognize and reuse.