La uzantnomo ne funkciis; tial la teknikisto petis novan.

Uzantnomo is a compound word: uzanto = user, and nomo = name. So it literally means user-name, i.e. username.

Esperanto very often combines roots into a single word instead of writing them separately. That is completely normal and one of the language’s most common word-building patterns.

In Esperanto, -is marks the past tense.

So:

• funkcii = to function / to work
• funkcias = works / is working
• funkciis = worked / was working

Since the sentence talks about something that happened in the past, funkciis is used.

Yes. Funkcii means to function, to operate, or to work.

So La uzantnomo ne funkciis means the username didn’t work or was not functioning properly. Esperanto often uses funkcii in places where English would use work for systems, devices, accounts, logins, and similar things.

Tial means therefore, for that reason, or so.

It connects the second clause to the first:

• La uzantnomo ne funkciis = the username didn’t work
• tial = therefore / so
• la teknikisto petis novan = the technician requested a new one

So tial shows that the second action happened as a result of the first.

The semicolon links two closely related complete clauses:

• La uzantnomo ne funkciis
• tial la teknikisto petis novan

This is similar to English punctuation. The semicolon shows a stronger break than a comma, but the ideas are still closely connected. A writer might also choose a period instead, but the semicolon works well here.

Petis is the past tense of peti, which means to ask for or to request.

Here it does not mean simply to ask a question. It means the technician requested something.

So:

• peti = to request / ask for
• petis novan = requested a new one

Because novan is the direct object of petis.

In Esperanto, direct objects take -n. Since the technician requested a new one, that thing being requested is the object, so nova becomes novan.

Compare:

• nova = new
• novan = new (as a direct object)

Here novan means a new one. The noun is omitted because it is understood from context.

The full idea would be:

• la teknikisto petis novan uzantnomon = the technician requested a new username

But Esperanto, like English, often leaves out a repeated noun when it is obvious. So novan stands on its own and means a new one.

Because the missing noun is still understood, and the adjective keeps the grammar that the full noun phrase would have had.

The full phrase would be:

• novan uzantnomon

Both words would be singular accusative:

• novan
• uzantnomon

When uzantnomon is left out, novan still keeps the -n to show that it is the direct object.

La is the definite article, meaning the.

It is used because the sentence is talking about specific, identifiable things:

• la uzantnomo = the particular username being discussed
• la teknikisto = the particular technician involved

Just like in English, the is used when the speaker assumes the listener can identify which person or thing is meant.