A despesa supérflua foi eliminada.

A is the feminine singular definite article, meaning the.

So:

• a despesa = the expense / the expenditure
• despesa on its own = expense / expenditure in a more general or indefinite sense

In this sentence, the speaker is talking about a specific expense, so a is used.

In Portuguese, every noun has grammatical gender. Despesa is a feminine noun, which is why it takes:

• the article a
• the adjective form supérflua
• the past participle form eliminada

They all agree with despesa.

A useful pattern is that many nouns ending in -a are feminine, though not always.

In Portuguese, adjectives often come after the noun, much more often than in English.

So:

• a despesa supérflua = the superfluous/unnecessary expense

This is the most neutral and natural order here.

You may sometimes see adjectives before the noun in Portuguese, but that often changes the tone, emphasis, or style. For ordinary description, noun + adjective is very common.

Supérflua means something like:

• superfluous
• unnecessary
• non-essential
• excess

In English, superfluous sounds a bit formal, and the same is true of supérfluo/supérflua in Portuguese. In everyday contexts, it can suggest something that is not needed and could be removed.

Because it describes despesa (feminine singular), it appears as supérflua.

The accent in supérflua shows the stressed syllable.

It is pronounced roughly with the stress on pér:

• su-PÉR-flua

Accent marks in Portuguese are important because they can show:

• where the stress falls
• sometimes vowel quality

So the accent is not optional; it is part of the correct spelling.

This is a passive construction.

It is made with:

• foi = was (from the verb ser, to be)
• eliminada = past participle of eliminar, agreeing with the feminine singular noun

So:

• foi eliminada = was eliminated

The whole sentence means that the expense received the action rather than performed it.

Compare:

• A empresa eliminou a despesa supérflua. = The company eliminated the unnecessary expense.
  
  • active
• A despesa supérflua foi eliminada. = The unnecessary expense was eliminated.
  
  • passive

Because in this passive structure, the past participle agrees with the noun being described: a despesa.

Since despesa is:

• feminine
• singular

the participle must also be:

• feminine
• singular

So:

• eliminado = masculine singular
• eliminada = feminine singular

Examples:

• O custo foi eliminado.
• A despesa foi eliminada.

Yes, depending on context.

Eliminar often means:

• to eliminate
• to remove
• to cut
• sometimes to do away with

In a financial or administrative context, English may naturally use:

• The unnecessary expense was eliminated.
• The unnecessary expense was removed.
• The unnecessary cost was cut.

So eliminated is a very direct translation, but not always the only natural one.

They are related, but not always identical.

• despesa often means expense, especially in accounting, budgeting, administration, or formal contexts
• gasto often means spending, expense, or outlay, and can sound a bit broader or more everyday depending on context

For example:

• reduzir despesas = to reduce expenses
• os gastos do mês = the month’s spending/expenses

In this sentence, despesa fits well because it sounds like a specific expense item being discussed formally.

Yes. Portuguese often uses active or alternative structures where English might use a passive.

For example:

• Eliminaram a despesa supérflua.
  = They eliminated the unnecessary expense.
• A despesa supérflua acabou por ser eliminada.
  = The unnecessary expense ended up being eliminated.
• Eliminou-se a despesa supérflua.
  = impersonal/passive-like structure, roughly The unnecessary expense was eliminated

But foi eliminada is perfectly correct and clear, especially in formal written Portuguese.

In European Portuguese, several unstressed vowels are reduced, so it may sound less fully pronounced than a learner expects from the spelling.

Very roughly:

• A may sound like a very short uh
• despesa may sound approximately like dsh-PEH-zuh
• supérflua may compress a bit in fast speech
• foi sounds roughly like foy
• eliminada may reduce some unstressed vowels

A rough learner-friendly approximation might be:

• uh dsh-PEH-zuh su-PER-floo-uh foy ee-lee-mee-NAH-duh

But that is only approximate. European Portuguese pronunciation tends to reduce unstressed vowels more than Brazilian Portuguese, so the spoken rhythm can feel tighter and less syllable-by-syllable than the spelling suggests.

Yes. Desnecessária is also possible and often very natural.

Compare:

• supérflua = superfluous, non-essential, slightly more formal
• desnecessária = unnecessary, often more everyday and straightforward

So both work, but the tone is a little different:

• A despesa supérflua foi eliminada.
  sounds more formal or administrative
• A despesa desnecessária foi eliminada.
  sounds slightly more direct and plain

Yes, that is also correct.

Both are grammatical:

• A despesa supérflua foi eliminada.
• Foi eliminada a despesa supérflua.

The second version puts the verb first and can sound a bit more formal, report-like, or stylistically marked. The first version is often easier for learners because it follows a more straightforward subject + verb pattern.

So the original sentence is a very good neutral model to learn from.