Se estus problemo kun mia konto, la laboristino de la banko helpus min tre pacience.

Because -us is the Esperanto conditional ending.

This sentence describes a hypothetical situation:

• Se estus problemo... = if there were a problem...
• ...la laboristino... helpus min... = ...the worker would help me...

A very important point for English speakers is that Esperanto often uses the conditional in both parts of this kind of unreal or imagined sentence. English usually says If there were..., she would help..., where the if clause looks like a past tense form. Esperanto does not do that here; it simply uses -us for the hypothetical idea.

The subject is problemo. It just comes after the verb.

So:

• estus problemo = there would be a problem / a problem would exist

This is a common pattern in Esperanto, especially in sentences that correspond to English there is / there was / there would be.

You can think of Se estus problemo as meaning:

• If a problem existed
• If there were a problem

English uses there as a dummy subject, but Esperanto does not need that kind of word here.

Because the sentence is talking about an unspecified problem, not a specific known one.

• problemo = a problem
• la problemo = the problem

Here the meaning is general: if there happened to be some problem with the account. Since it is not a particular already-identified problem, no la is used.

Kun literally means with, but in many contexts it can mean something like connected with, involving, or concerning.

So:

• problemo kun mia konto = a problem with my account

This is a natural way to express that the problem is related to the account.

A learner might expect something more like about my account, but kun works very naturally in Esperanto in this kind of expression.

It means female worker.

Breakdown:

• labor- = work
• -ist- = a person associated with an activity, profession, or role
• -in- = female
• -o = noun ending

So:

• laboristo = worker
• laboristino = female worker

In this sentence, la laboristino de la banko means the female worker or employee of the bank.

If the person's sex were not important, Esperanto could simply use laboristo.

De often means of or from.

Here it shows association:

• la laboristino de la banko = the worker of the bank
• more natural English: the bank employee or the woman working at the bank

So de la banko identifies which worker is meant.

Because min is the direct object form.

• mi = I
• min = me

In the sentence, the bank worker is helping me, so me is the object of helpus.

Esperanto marks direct objects with -n:

• La laboristino helpus min = The worker would help me

This -n ending is called the accusative ending.

Yes. In normal Esperanto, helpi is used directly with the person or thing being helped.

So:

• helpi min = help me
• helpi ŝin = help her
• helpi amikon = help a friend

That is why min appears without a preposition.

This is worth noticing because some languages use a preposition where Esperanto does not.

Because pacience is an adverb, and it describes how she would help.

• pacienca = patient, as an adjective
• pacience = patiently, as an adverb

Here the word modifies the verb helpus, not a noun:

• helpus min tre pacience = would help me very patiently

If you used pacienca, it would need to describe a noun, such as:

• pacienca laboristino = a patient worker

Yes, Esperanto word order is fairly flexible, though some orders sound more natural than others.

The original sentence is completely natural:

• Se estus problemo kun mia konto, la laboristino de la banko helpus min tre pacience.

But some parts could move, especially adverbs:

• Se estus problemo kun mia konto, la laboristino de la banko tre pacience helpus min.

That still works.

However, the original version is smooth and clear, so it is a good model to follow.

No. That would be a different meaning.

The given sentence is hypothetical:

• Se estus... helpus... = If there were..., would help...

It suggests an imagined or uncertain situation.

If you wanted a more real or likely future condition, Esperanto would normally use future forms instead:

• Se estos problemo kun mia konto, la laboristino de la banko helpos min tre pacience.

So the difference is:

• estus / helpus = hypothetical, imagined
• estos / helpos = future, more real possibility