Ao embarcar, eu sempre procuro meu assento perto da janela.

Ao + infinitive is a very common Portuguese structure meaning when, upon, or while doing something.

So ao embarcar means something like:

• when boarding
• upon boarding
• as I board

It is built with ao + an infinitive verb:

• ao chegar = when arriving
• ao sair = when leaving
• ao entrar = when entering

It often sounds a little more compact and elegant than a full clause like quando embarco.

Embarcar specifically means to board a plane, ship, bus, or similar means of transportation.

So in travel contexts, embarcar is the most natural verb for boarding.

Compare:

• embarcar no avião = to board the plane
• entrar no avião = to enter the plane

Both can be understood, but embarcar is more precise and more standard in airport/travel language.

No, eu is not strictly necessary here.

Portuguese verbs usually show the subject clearly, and procuro already tells you the subject is I.

So these both work:

• Ao embarcar, eu sempre procuro...
• Ao embarcar, sempre procuro...

Including eu can:

• add a little emphasis
• make the sentence slightly clearer
• sound more natural in some contexts

Brazilian Portuguese uses subject pronouns more often than European Portuguese, so eu does not sound strange here.

In Brazilian Portuguese, both are possible:

• meu assento
• o meu assento

The version without the article is very common and natural in Brazil, especially in everyday speech.

Very roughly:

• meu assento = more direct, very common
• o meu assento = also correct, sometimes a bit more explicit or emphatic

So procuro meu assento is perfectly normal.

Procuro is the present indicative of procurar.

Here it expresses a habitual action:

• eu sempre procuro = I always look for / I always search for

Portuguese often uses the simple present for habits, just like English does in sentences such as I always look for my seat.

If you said estou procurando, that would usually mean you are looking for it right now, at this moment, rather than describing a general habit.

Assento means seat.

In this sentence, it is the best general word.

Other options are a bit different:

• assento = seat, neutral and accurate
• poltrona = seat/armchair; very common for buses and planes in Brazil
• lugar = place/spot; less specific than seat
• cadeira = chair; usually not the best word for an airplane seat

So for travel situations, assento is a very good choice.

Perto normally takes the preposition de:

• perto de = near

Then de combines with the feminine article a before janela:

• de + a = da

So:

• perto da janela = near the window

This kind of contraction is extremely common in Portuguese:

• de + o = do
• de + a = da
• de + os = dos
• de + as = das

Not exactly.

• perto da janela = near the window
• ao lado da janela = next to the window
• na janela can sometimes be used in travel contexts to mean by the window or window seat

So perto da janela is understandable and natural, but it is a little broader.

If you want to be more exact about a window seat, Brazilians often say things like:

• assento na janela
• assento ao lado da janela
• poltrona na janela

Because Ao embarcar is an introductory adverbial expression at the beginning of the sentence.

The comma helps separate that opening idea from the main clause:

• Ao embarcar, eu sempre procuro...

This is very common and stylistically natural in Portuguese.

Without the comma, the sentence might still be understood, but the comma is the better standard choice here.

Yes. Portuguese allows some flexibility.

For example, these are possible:

• Ao embarcar, eu sempre procuro meu assento perto da janela.
• Ao embarcar, sempre procuro meu assento perto da janela.
• Eu sempre procuro meu assento perto da janela ao embarcar.

The original version sounds very natural because it sets the time/context first, then gives the main action.

Putting ao embarcar at the end is possible, but it may sound a little less smooth in this case.

Very often, yes.

In eu sempre procuro, sempre is in a very natural position: before the main verb.

That is one of the most common placements for adverbs of frequency in Portuguese:

• eu sempre chego cedo
• ela nunca come carne
• nós geralmente viajamos em julho

You may also hear other placements in real speech, but eu sempre procuro is standard and very natural.