Imprimanta este lângă ecran, dar tastatura este pe alt birou.

Because Romanian often puts the definite article at the end of the noun, not in front of it.

• imprimantă = printer

• imprimanta = the printer

• tastatură = keyboard
• tastatura = the keyboard

This is one of the biggest differences from English.

Este is the 3rd person singular of a fi = to be.

So here it means is.

• imprimanta este = the printer is
• tastatura este = the keyboard is

In everyday speech, many speakers also use the shorter form e:

• Imprimanta e lângă ecran.

That is more informal, but very common.

In Romanian, a noun after a preposition can sometimes appear without the definite article, especially in simple location expressions.

So lângă ecran is natural as a basic spatial phrase: near/by the screen.

If you want to make the noun more explicitly definite or more specific, you can also get forms like:

• lângă ecranul calculatorului = near the computer’s screen
• lângă ecranul mare = near the big screen

So the bare form ecran here is not strange; it is a normal way to express location.

Because birou is a neuter noun, and in the singular, neuter nouns behave like masculine nouns for agreement.

That is why the adjective takes the masculine singular form:

• alt birou = another/different desk

Compare:

• masculine: alt băiat
• feminine: altă fată
• neuter singular: alt birou

So alt birou is correct.

Many Romanian adjectives do often come after the noun, but alt is one of the words that normally comes before it.

So:

• alt birou = another desk / a different desk

This is normal Romanian word order.
You should think of alt as behaving a bit like a determiner in this kind of phrase.

They are prepositions showing location.

• lângă = near / next to / by
• pe = on

So the sentence uses two different location phrases:

• lângă ecran
• pe alt birou

They tell you where each object is.

Usually not in a way you can see here.

These prepositions are followed by the accusative, but for ordinary nouns, the accusative form is often the same as the basic dictionary form. So:

• ecran
• birou

stay the same in this sentence.

This is why English speakers often do not notice Romanian case right away in simple examples like this.

In normal, clear Romanian, yes, repeating este is the most natural full form:

• Imprimanta este lângă ecran, dar tastatura este pe alt birou.

You may hear omission in very informal or elliptical speech, but for learners, it is best to keep both verbs. It sounds complete and standard.

Because dar means but, and in Romanian it is normally preceded by a comma when it connects two clauses.

So:

• ..., dar ...

is standard punctuation.

A helpful approximation is LUHN-guh, but not exactly in an English way.

More carefully:

• â is a Romanian vowel with no exact English equivalent
• ă sounds like the a in about

So lângă is approximately /ˈlɨŋ.gə/.

The first syllable is stressed: LÂN-gă.

The pattern is very straightforward:

• Subject + este + place expression
• Subject + este + place expression

So:

• Imprimanta
  • este
    • lângă ecran
• tastatura
  • este
    • pe alt birou

This is a very useful Romanian sentence pattern for describing where things are.

Yes. Pe un alt birou is also correct.

The version with un makes the noun feel a bit more explicitly indefinite:

• pe alt birou
• pe un alt birou

Both are possible, and both are natural. The sentence you were given is slightly leaner and very normal.

They are:

• imprimantă — feminine
• tastatură — feminine
• ecran — neuter
• birou — neuter

This matters because gender affects articles and adjective forms:

• imprimanta
• tastatura
• alt birou

So even in a short sentence like this, gender is doing a lot of work.