Learn Hardcore Portuguese (Portugal): Eu vejo uma casa grande.

Eu vejo uma casa grande = I see a big house (neutral, may add slight emphasis on I).
Vejo uma casa grande = I see a big house (perfectly natural and very common).

You normally keep eu:

for contrast or emphasis: Eu vejo uma casa grande, mas tu não vês nada.
when starting a sentence in careful speech, or when you want to be extra clear.

In everyday conversation, Vejo uma casa grande is absolutely fine and very typical.

Why is it vejo and not ver in the sentence?

Ver is the infinitive (the dictionary form: to see).
Vejo is the present tense, first person singular form: I see.

Tiny conjugation of ver (present indicative):

eu vejo – I see
tu vês – you (singular, informal) see
ele/ela vê – he/she sees
nós vemos – we see
vocês veem – you (plural) see
eles/elas veem – they see

So in Eu vejo uma casa grande, vejo matches the subject eu.

What is the difference between vejo, olho, and estou a ver?

vejo = I see (general perception, what is in your field of vision).
olho (from olhar) = I look or I look at (you actively direct your eyes).
estou a ver = I am seeing / I’m watching (an ongoing action), the European Portuguese continuous form.

Examples:

Vejo uma casa grande. – I see a big house.
Olho para a casa. – I look at the house.
Estou a ver uma casa grande ao longe. – I’m seeing / I’m currently looking at a big house in the distance.

In European Portuguese, the normal continuous form is estar a + infinitive: estou a ver, not estou vendo (that’s Brazilian).

Why is it uma and not um?

Because casa is a feminine noun, and the indefinite article must agree in gender.

um – masculine singular (e.g. um carro, a car)
uma – feminine singular (e.g. uma casa, a house)

So:

uma casa grande – a big house (feminine)
um carro grande – a big car (masculine)

The article’s form matches the noun, not the speaker.

How do I know that casa is feminine?

You mostly have to learn the gender of each noun, but there are patterns that help:

Many nouns ending in -a are feminine: casa, porta, mesa, janela.
Many nouns ending in -o are masculine: carro, livro, quadro.

There are exceptions, but casa follows the typical pattern. In dictionaries, you’ll often see:

casa (f) or casa, s.f. = feminine noun.

Whenever you learn a new noun, it’s good to learn it with its article:

uma casa, a casa – that fixes the gender in your mind.

Why does grande come after casa? Can it go before the noun?

The default position of most adjectives in Portuguese is after the noun:

uma casa grande – a big house
um carro vermelho – a red car

Grande can go before the noun, but the meaning usually changes:

uma casa grande = a big house (physically large)
uma grande casa = a great house / an excellent house (quality, importance, not just size)

So in your sentence, uma casa grande clearly means the house is big in size.

If casa is feminine, why isn’t it granda instead of grande?

Adjectives in -e (like grande) have the same form for masculine and feminine in the singular:

um carro grande – a big car (masculine)
uma casa grande – a big house (feminine)

They only change in the plural:

carros grandes – big cars
casas grandes – big houses

So:

masculine singular: grande
feminine singular: grande
masculine plural: grandes
feminine plural: grandes

Can Eu vejo uma casa grande ever mean “I see a great house” instead of just “a big house”?

Not really; in this word order, uma casa grande is understood as a big house (size).

To express the idea of “great” or “impressive” house, you would normally move grande before the noun:

Eu vejo uma grande casa. – I see a great / impressive house.

So:

casa grande → big-sized house
grande casa → great / important / impressive house

Is the word order flexible? Could I say Eu uma casa grande vejo?

No, not in normal, natural speech. Portuguese usually follows Subject–Verb–Object (SVO), similar to English:

Eu vejo uma casa grande. – I see a big house.

You can drop the subject pronoun:

Vejo uma casa grande.

But you cannot freely scramble the words like Eu uma casa grande vejo; that sounds wrong. Word order can change in more advanced, literary, or emphatic structures, but the basic learner-safe pattern is:

(Subject) + Verb + Object + Adjectives
→ (Eu) vejo uma casa grande.

How do I pronounce Eu vejo uma casa grande in European Portuguese?

Very roughly, using English-like hints:

Eu – like “eh-oo” blended together; often sounds close to “ehw” or even just /eʊ/.
vejo – ve like “veh”, jo with the Portuguese j like the “s” in measure: VEH-zhu.
uma – OO-ma.
casa – KAH-zah (the s between vowels sounds like z).
grande – GRUND (final -e is very reduced, almost just grun-d).

Spoken quickly in European Portuguese, it can sound like:

[eʊ ˈveʒu uma ˈkazɐ ˈɡɾɐ̃d(ɨ)], with the -e in grande very weak or almost gone.