Tuj kiam la transpago alvenos, mi kontrolos la saldon.

Tuj kiam is a set phrase meaning as soon as.

• tuj = immediately, right away
• kiam = when

So together, they introduce an event that happens immediately after another one. It is very natural Esperanto.

A few similar expressions are:

• kiam = when
• post kiam = after
• antaŭ ol = before
• tuj kiam = as soon as

This is a very common question for English speakers.

In Esperanto, it is normal to use the future ending -os in a subordinate clause if the action is genuinely in the future.

So:

• Tuj kiam la transpago alvenos... = As soon as the transfer arrives...
• ...mi kontrolos la saldon. = ...I will check the balance.

English avoids will after when/as soon as, but Esperanto does not have to follow that rule. Esperanto looks more directly at the time of the action: if it is future, -os is perfectly natural.

So the future is shown in both clauses because both events are in the future.

Usually, in this context, alvenos is the clearer and more standard choice, because the transfer has not arrived yet.

Using alvenas would sound more like:

• a habitual situation
• a general truth
• or a more stylistic/non-literal way of speaking

For a specific future event, Esperanto normally prefers:

• Tuj kiam la transpago alvenos, mi kontrolos la saldon.

So if you mean one transfer in the future, alvenos is the best form.

Transpago refers to a transfer of money, especially a payment transfer. In many contexts, it can indeed mean a bank transfer or funds transfer.

It is built from:

• trans- = across, from one place/account to another
• pago = payment

So the word suggests a payment moved from one account or party to another.

Depending on context, Esperanto speakers might also use other terms in financial language, but transpago is understandable and fits this sentence well.

Yes. Alveni literally means to arrive, and it can be used not only for people and objects, but also for things like:

• a letter
• a message
• a payment
• a transfer

So la transpago alvenos means the transfer will arrive, in the sense that it will be received or show up in the account/system.

This is similar to English expressions like:

• The payment has arrived
• The funds came through

Because la saldon is the direct object of kontrolos.

In Esperanto, the direct object takes -n.

• saldo = balance
• saldon = balance as the thing being checked

So:

• mi kontrolos la saldon = I will check the balance

This -n ending is one of the most important parts of Esperanto grammar.

La is the definite article, meaning the.

Here it shows that the speaker has a specific transfer and a specific balance in mind.

• la transpago = the transfer
• la saldon = the balance

Without la, the sentence would sound more general or less specific. In this context, we are talking about a particular transfer and a particular account balance, so la makes sense.

Yes. Saldo is the usual Esperanto word for balance, especially in financial contexts such as:

• account balance
• remaining balance
• current balance

So kontroli la saldon is a natural way to say check the balance.

Yes. Esperanto word order is fairly flexible, though some versions are more neutral than others.

The given sentence is very natural:

• Tuj kiam la transpago alvenos, mi kontrolos la saldon.

You could also say:

• Mi kontrolos la saldon tuj kiam la transpago alvenos.

That means the same thing. The difference is mainly emphasis:

• starting with Tuj kiam... emphasizes the time condition first
• starting with Mi kontrolos... emphasizes the main action first

Both are correct.

It often covers all of those ideas, depending on context.

In this sentence, kontroli is most naturally to check. It can also suggest verifying or looking to make sure something is correct.

So mi kontrolos la saldon most naturally means:

• I’ll check the balance
• I’ll look at the balance
• I’ll verify the balance

In everyday use, check is the best English match here.