Learn Hardcore Portuguese (Portugal): Assim que tivermos chegado a casa, teremos tempo para falar com calma. - As soon as we have arrived home, we will have time to talk calmly.

It’s formed as: future subjunctive of “ter” + past participle of the main verb.
- ter in the future subjunctive:
  - eu tiver
  - tu tiveres
  - ele/ela/você tiver
  - nós tivermos
  - vocês/eles/elas tiverem
- past participle of chegar: chegado

So “tivermos chegado” = nós tivermos chegado = when/as soon as we have arrived (referring to the future).

It expresses an action that will already be completed before another future action (teremos tempo para falar…).

Why is the subjunctive used after “Assim que” here? Why not an ordinary future tense?

In Portuguese, when you talk about a future event introduced by time conjunctions like:

assim que (as soon as)
quando (when)
logo que (as soon as)
depois que / depois de que (after)

you normally use the future subjunctive, not the future indicative.

So:

Assim que tivermos chegado a casa, teremos tempo…
Literally: As soon as we *will have arrived home, we will have time…
(English uses a present perfect after *as soon as; Portuguese uses future perfect subjunctive.)

If the clause referred to a habitual/general situation, you’d use the present indicative instead:

Assim que chegamos a casa, jantamos.
As soon as we get home, we have dinner. (every day, as a routine)

But because our sentence is future and not a general habit, subjunctive is required.

Could we say “Assim que chegarmos a casa” instead of “Assim que tivermos chegado a casa”? Are both correct?

Yes, both are grammatically correct in European Portuguese, but there is a slight nuance:

Assim que chegarmos a casa…
- Uses the simple future subjunctive (chegarmos).
- Focuses on the moment of arrival as the point when the next action can start.
Assim que tivermos chegado a casa…
- Uses the future perfect subjunctive (tivermos chegado).
- Emphasises that the act of arriving is fully completed and you’re already in the state of having arrived (settled in), before you have time to talk.

In practice, in everyday speech, many people would more naturally say:

Quando / Assim que chegarmos a casa, vamos ter tempo para falar com calma.

The compound future subjunctive (tivermos chegado) tends to sound a bit more formal or written and adds that extra sense of “once we’re properly there / once arrival is fully done”.

Why is it “chegado a casa” and not “chegado em casa” in European Portuguese?

In European Portuguese, the verb chegar normally takes the preposition a for destinations:

chegar a casa – to arrive home
chegar a Lisboa – to arrive in Lisbon
chegar ao aeroporto – to arrive at the airport

So the standard pattern is: chegar a + lugar.

In Brazilian Portuguese, in everyday speech it’s very common to hear “chegar em casa”, “chegar no aeroporto”, etc., but in Portugal the norm is strongly “chegar a …”.

So, for European Portuguese learners, you should treat “chegar a (um lugar)” as the default rule.

Why is it “a casa” and not “à casa”? What’s the difference?

“a casa” (with no accent) = just the preposition “a”
- the noun casa (without an article).
“à casa” (with accent) = contraction of a + a (preposition a
- the definite article a = the):
  - a + a casa → à casa

In this sentence, “casa” means “home” in a general sense, not the house as a specific building. In that meaning, Portuguese normally omits the article:

chegar a casa – to arrive home
ir para casa – to go home
estar em casa – to be at home

You would use “à casa” when you’re talking about a specific house with the article:

chegar à casa da Maria – arrive at Maria’s house
voltar à casa antiga – return to the old house

So here, “a casa” correctly means “(to) home”, not “to the house”.

Why is there no article at all before “casa” in “chegado a casa”? Don’t nouns usually need one?

Portuguese often drops the article with some very common nouns when they are used in a generic, functional sense, especially with verbs of movement:

Typical examples (especially in European Portuguese):

casa – home
- ir para casa, chegar a casa, estar em casa
escola – school
- ir para a escola, estar na escola (here the article often appears, but you can also find “estar em escola” in fixed expressions)
cama – bed
- ir para a cama, estar na cama
trabalho – work
- ir para o trabalho, estar no trabalho

With casa = home, especially after chegar, the most idiomatic form is without an article: chegar a casa.

When you’re talking about a particular house (as a building or property), you use an article:

a casa nova, a casa do João, a casa à beira-mar, etc.

Could we say “teremos tempo de falar com calma” instead of “tempo para falar com calma”?

Yes, both “tempo para + infinitive” and “tempo de + infinitive” are possible. In European Portuguese:

ter tempo para fazer algo
ter tempo de fazer algo

are both common and correct.

There is no strong difference in meaning. If anything, in some contexts:

tempo para can feel slightly more neutral and is extremely frequent.
tempo de can sometimes carry a nuance of opportunity or chance, but in many cases they’re interchangeable.

So you could perfectly say:

Assim que tivermos chegado a casa, teremos tempo de falar com calma.

The original “tempo para falar” is just a very natural, standard choice.

What exactly does “falar com calma” mean? Is it “speak calmly” or “speak slowly”?

“Falar com calma” literally means “to speak with calm”, but idiomatically it is closer to:

to talk calmly / without rushing / in a relaxed way
to have an unhurried, peaceful conversation

It can include:

speaking in a calm tone (not angry, not agitated), and/or
speaking without being in a hurry, with enough time to explain things properly.

It does not necessarily mean to speak slowly (that would be more like “falar devagar”), although speaking calmly often results in a somewhat slower pace.

Why do we have “teremos tempo” instead of “vamos ter tempo”? Are both acceptable?

Both forms are acceptable in European Portuguese, but there is a nuance:

teremos tempo – synthetic future (futuro do indicativo), slightly more formal or neutral.
vamos ter tempo – periphrastic future (ir + infinitive), tends to sound more colloquial and everyday.

In speech, many people prefer “vamos ter tempo para falar com calma”.
In writing, especially in more careful or formal style, “teremos tempo” is very natural.

Meaning-wise, in this sentence they are essentially equivalent.

Can the order of the clauses be changed, or must it start with “Assim que tivermos chegado a casa”?

You can absolutely change the order. Both are correct:

Assim que tivermos chegado a casa, teremos tempo para falar com calma.
Teremos tempo para falar com calma assim que tivermos chegado a casa.

The meaning is the same. A few notes:

The comma is normally used only when the subordinate clause comes first:
- Assim que tivermos chegado a casa, teremos tempo…
- But: Teremos tempo… assim que tivermos chegado a casa. (usually no comma here)
Starting with “Assim que tivermos chegado a casa” slightly emphasises the condition / timing (“once we’re home”), while starting with “Teremos tempo…” emphasises the result (“we’ll have time”).

Is this sentence specifically European Portuguese? Would Brazilian Portuguese say it differently?

The sentence is perfectly correct in both varieties, but typical usage differs slightly.

European Portuguese (very natural):

Assim que tivermos chegado a casa, teremos tempo para falar com calma.
or, more colloquially: Assim que chegarmos a casa, vamos ter tempo para falar com calma.

Brazilian Portuguese (everyday speech) would more likely say:

Assim que a gente chegar em casa, vamos ter tempo para conversar com calma.
(note a gente, chegar em casa, conversar instead of falar)

Points of difference:

EP strongly prefers “chegar a casa”; BR normally says “chegar em casa” in speech.
EP uses nós tivermos chegado / nós chegarmos; BR very often uses a gente chegar in informal contexts.
Both varieties understand each other; the original sentence is fully understandable in Brazil, just a bit more formal / European-sounding.