O prejuízo foi grande.

O is the masculine singular definite article, meaning the.

In Portuguese, it is very common to use the definite article before nouns where English might or might not use the. So o prejuízo means the loss / the damage / the financial loss, depending on context.

You could sometimes say just prejuízo, but that would usually sound more general or dictionary-like, not as tied to a specific situation.

Prejuízo often means:

• loss
• damage
• financial loss
• sometimes harm or disadvantage, depending on context

A very important warning for English speakers: prejuízo does not mean English prejudice.

Even though they look similar, they are different words:

• prejuízo = loss, damage, harm
• preconceito = prejudice

So this sentence is talking about some kind of loss or damage, not bias or discrimination.

Foi is the third-person singular preterite of ser.

Here:

• o prejuízo = singular subject
• so the verb must also be singular
• foi = was

This tense is used to describe something as a completed fact in the past.

So O prejuízo foi grande presents the loss as a past event or result that is seen as complete.

Portuguese often uses ser for characteristics, identity, classification, or evaluation, and estar for states or conditions.

In this sentence, grande is being used as an evaluation of the loss: it was big/significant. That is why ser sounds natural here.

So:

• foi grande = was great / was significant / was large
• esteve grande would sound unnatural here

With amounts, size, value, importance, and general assessment, ser is the normal choice.

Because in Portuguese, adjectives usually come after the noun or after a linking verb like ser.

This sentence has the structure:

• O prejuízo = subject
• foi = linking verb
• grande = adjective complement

So it works like:

• The loss
  • was
    • big/significant

That word order is completely normal in Portuguese.

Grande is an adjective that has the same form for masculine singular and feminine singular:

• o prejuízo grande
• a perda grande

For the plural, it changes:

• grandes

So:

• singular: grande
• plural: grandes

That is why here, with singular prejuízo, the adjective is grande.

Yes. In this sentence, grande is probably not about physical size at all.

It can mean:

• large
• great
• serious
• significant
• considerable

With something like prejuízo, grande usually means the loss was substantial or serious, often financially.

So even if the meaning shown to the learner is big, the natural English interpretation may often be The loss was significant or The damage was considerable.

A useful approximate pronunciation is:

preh-zhoo-EE-zoo

A few notes:

• j in Portuguese sounds like the s in measure or the zh sound
• the stress falls on í: pre-ju-Í-zo
• the final o in Brazilian Portuguese is often pronounced like oo

So the stressed part is:

• pre-ju-Í-zo

The accent mark in prejuízo shows the stressed syllable:

• pre-ju-Í-zo

Without getting too technical, the accent helps show that the stress does not fall where you might otherwise expect it.

For learners, the main thing to remember is:

• the stress is on í

So do not say pre-JU-i-zo or PRE-ju-i-zo. The strongest syllable is Í.

It is masculine.

You can tell because the sentence uses:

• o prejuízo

That also affects other words that agree with it, such as articles and some adjectives.

Examples:

• o prejuízo
• um prejuízo enorme
• os prejuízos foram grandes

Yes, but the meaning changes slightly.

• O prejuízo foi grande = the loss was large, presented as a completed fact
• O prejuízo era grande = the loss was large, but with a more descriptive, ongoing, background, or less bounded feeling

Very roughly:

• foi = completed past event/fact
• era = description/background in the past

Both are possible, but foi grande sounds more like a conclusion or result.

Yes, if you are talking about more than one loss or multiple damages:

• Os prejuízos foram grandes.

Notice the changes:

• o → os
• prejuízo → prejuízos
• foi → foram
• grande → grandes

Everything has to agree with the plural subject.

Yes, it is very natural.

It sounds like something you might hear in contexts such as:

• business
• accidents
• storms
• lawsuits
• bad investments
• agriculture
• repairs
• news reports

It is a simple and common way to say that the loss or damage was substantial.

Yes, depending on the exact context.

Some possibilities are:

• perda = loss
• dano = damage
• estrago = damage, mess, destruction
• rombo = major financial hole/loss, more informal or vivid in some contexts

The difference is that prejuízo often strongly suggests financial loss or measurable harm, while the others may fit different situations better.

So O prejuízo foi grande is especially natural when the loss is economic, practical, or quantifiable.