Learn Hardcore Portuguese (Portugal): O artigo científico é difícil.

O artigo científico é difícil.
This uses the definite article o (the). It usually implies:
- a specific article that both speaker and listener know about:
  - “The scientific article (we’re talking about) is difficult.”
- or sometimes “the scientific article as a type” in a more generic statement, especially in explanations or teaching.
Um artigo científico é difícil.
This uses the indefinite article um (a). It sounds more like:
- “A scientific article is difficult (to write / to understand).”
- You’re talking about any typical scientific article, not one specific one.

In practice:

If you mean that particular paper the student is reading: use o.
If you mean scientific articles in general, as a type of text: you can use um, or more naturally the plural: Os artigos científicos são difíceis. (“Scientific articles are difficult.”)

Why is científico after artigo and not before it, like in English (“scientific article”)?

In Portuguese, the default position for most adjectives is after the noun:

artigo científico = “scientific article”
carro novo = “new car”
livro interessante = “interesting book”

So artigo científico is the normal, neutral order.

Adjectives can sometimes appear before the noun, but:

that’s less common,
it often adds a nuance (more subjective, emotional, poetic, or emphasizing a quality).

✗ científico artigo is not natural Portuguese.
You should say artigo científico.

Does científico agree with artigo in gender and number?

Yes. In Portuguese, most adjectives must agree in gender and number with the noun:

artigo científico – masculine, singular
artigos científicos – masculine, plural
revista científica (“scientific journal”) – feminine, singular
revistas científicas – feminine, plural

So:

masculine singular: científico
feminine singular: científica
masculine plural: científicos
feminine plural: científicas

In the sentence O artigo científico é difícil, artigo is masculine singular, so científico is also masculine singular.

Which verb is é here, and why not está? What’s the difference between ser and estar in this sentence?

É is the 3rd person singular of ser (“to be”).

Portuguese has two main verbs for “to be”:

ser – for more permanent, inherent, or defining characteristics
estar – for more temporary, changing, or current states

In O artigo científico é difícil:

We’re describing difficulty as an inherent characteristic of that article (or of scientific articles as a type).
So we naturally use ser: é difícil.

If you said O artigo científico está difícil, it would be unusual. It might be used in specific, informal contexts to suggest:

“Right now it’s hard (to deal with / to understand),” as a temporary situation,
but for describing how difficult a text is, ser is the normal verb: é difícil.

Why is difícil the same for masculine and feminine? Does it change form?

Adjectives in Portuguese fall into two main patterns:

Two-form adjectives (different for masculine and feminine):
- cansado / cansada (“tired”)
- bonito / bonita (“pretty”)
Invariable-for-gender adjectives (same form for masculine and feminine):
- difícil
- feliz
- grande

Difícil is in the second group:

masculine singular: difícil
feminine singular: difícil
masculine plural: difíceis
feminine plural: difíceis

So:

O artigo científico é difícil.
A tese é difícil.
Os artigos científicos são difíceis.
As teses são difíceis.

How are artigo, científico, and difícil pronounced in European Portuguese?

Approximate European Portuguese pronunciation (Lisbon standard):

artigo → [ɐɾˈtiɣu]
- r is a light tap [ɾ] between vowels (like Spanish single r).
- Final -o is pronounced close to u ([u]).
- g before o is a hard g.
científico → [sjẽˈtifiku]
- ci- before vowel = [si] → then quickly [sje] at the start, often sounding like “syen”.
- The stressed syllable is -tí-; the accent í marks this.
- Final -o again ~[u].
difícil → [diˈfisil]
- Stressed on -fí-, marked by the accent.
- Final -l is a clear [l], not a dark English l.

Spoken naturally in European Portuguese, the sentence is roughly:
[u ɐɾˈtiɣu sjẽˈtifiku e diˈfisil]

Why do científico and difícil have accent marks?

In Portuguese, written accents mainly show:

Where the stress falls (which syllable is stressed).
Sometimes, which vowel quality (open vs. closed) you should use.

Basic stress rule (without an accent):

Words ending in -a, -e, -o, -as, -es, -os, -am, -em are usually stressed on the second-to-last syllable.
Other endings are usually stressed on the last syllable.

Científico:

Ends in -o, so without an accent the stress would be on ti as well, but the accent í makes this very clear and also indicates the vowel quality.
Syllables: ci-en-TÍ-fi-co → científico.

Difícil:

Ends in -l, which would normally make it stressed on the last syllable (di-fi-CIL).
But Portuguese actually stresses the second-to-last syllable: di-FÍ-cil.
The accent í marks this irregular stress.

So:

científico → stress on tí
difícil → stress on fí

Could I say É difícil o artigo científico instead? Is the word order flexible?

Yes, Portuguese word order is somewhat flexible, but there are differences in neutrality and emphasis.

O artigo científico é difícil.
– This is the most neutral and common order: Subject – Verb – Complement.
É difícil o artigo científico.
– Grammatically correct, but it has a slightly different focus:
You first state the evaluation (“It is difficult”) and then specify what is difficult.
It can sound more emphatic or stylistic:
– “It’s difficult, the scientific article.”

In everyday speech, learners should generally stick with the neutral order:

O artigo científico é difícil.

Does artigo here mean a grammatical article (like “the, a, an”), or a written article (like a paper)?

Artigo in Portuguese can mean both, depending on context:

Grammatical article (like “the, a, an”):
- artigo definido = definite article (o, a, os, as)
- artigo indefinido = indefinite article (um, uma, uns, umas)
Written article (newspaper article, journal article, scientific paper):
- artigo de jornal = newspaper article
- artigo científico = scientific article / academic paper

In O artigo científico é difícil, the presence of científico clearly points to meaning 2: an academic/scientific paper, not a grammatical article.

Does this sentence talk about one specific article or scientific articles in general?

On its own, O artigo científico é difícil most naturally suggests one specific article:

“The scientific article (we’re referring to) is difficult.”

To talk clearly about scientific articles in general, it’s more natural to use the plural:

Os artigos científicos são difíceis.
→ “Scientific articles are difficult.”

However, in certain teaching or explanatory contexts, speakers may use the singular with o to represent a type:

O artigo científico é um texto formal.
→ “The scientific article is a formal text” (meaning “this type of text is formal”).

But for learners, if you mean “in general,” prefer:

Os artigos científicos são difíceis.

Can I drop the article and just say Artigo científico é difícil?

In normal, full sentences in Portuguese, you usually need an article with singular countable nouns:

O artigo científico é difícil. ✅ natural
Artigo científico é difícil. ❌ odd in everyday speech

You might see no article:

in titles, headings, lists, or notes:
- Artigo científico difícil de compreender (as a title or bullet point)
in some set expressions or very colloquial speech.

But as a standard sentence, especially for learners, you should keep the article:

O artigo científico é difícil.