Learn Hardcore Portuguese (Portugal): Se eu respeitar a hora de ir para a cama, o dia seguinte corre melhor. - If I respect the bedtime, the next day goes better.

Portuguese uses the future subjunctive after conjunctions like se, quando, assim que, logo que when we’re talking about a possible future situation:

Se eu respeitar a hora de ir para a cama, o dia seguinte corre melhor.
If I stick to my bedtime, the next day goes better.
Quando eu chegar a casa, ligo‑te.
When I get home, I’ll call you.

In English we normally use a present tense (if I stick, when I get), but in Portuguese it’s this special future subjunctive form.

Could you say “Se eu respeito a hora de ir para a cama” instead? What would be the difference?

You can say “Se eu respeito a hora de ir para a cama”, and it’s grammatically correct, but it’s less natural in European Portuguese in this context.

Se eu respeito a hora de ir para a cama, o dia seguinte corre melhor.
Sounds more like a statement about a habitual fact or principle, but many speakers would still prefer the future subjunctive here.
Se eu respeitar a hora de ir para a cama, o dia seguinte corre melhor.
This is what most speakers would actually say. It still implies a general rule, but uses the normal pattern after se for a condition that could be (and often is) fulfilled in the future.

So:

After se with a conditional future meaning, the future subjunctive (respeitar) is by far the most idiomatic choice.
Se eu respeito… is not wrong, but it sounds more like “Given that I do respect…” or “Whenever I respect…”, and is less typical here.

What does “respeitar a hora” literally mean, and is respeitar commonly used this way?

Literally, respeitar a hora means “to respect the time”.

In practice, it means:

to stick to a time
to keep to a schedule
to obey a set time

So “respeitar a hora de ir para a cama” is really “to stick to/keep to my bedtime”.

This use of respeitar is very common in Portuguese:

respeitar os prazos – to meet deadlines
respeitar as regras – to follow/obey the rules
respeitar o limite de velocidade – to respect the speed limit
respeitar os horários – to stick to the timetables

So the sentence is very natural: you’re “respecting” your agreed bedtime.

Why is it “a hora de ir para a cama” and not “a hora para ir para a cama”? What does “hora de + infinitive” mean?

In Portuguese, “hora de + infinitive” is a fixed pattern that means “time to do something”.

Examples:

Está na hora de comer. – It’s time to eat.
É hora de estudar. – It’s time to study.
Chegou a hora de decidir. – The time has come to decide.

So:

a hora de ir para a cama = literally “the hour of going to bed” → bedtime

Using “hora para + infinitive” is possible in some contexts, but it’s less idiomatic, and here it would sound off. Native speakers strongly prefer “hora de + infinitive” for this “time to do X” meaning.

Could you also say “a hora de deitar” or “a hora de me deitar” instead of “a hora de ir para a cama”?

Yes, both are possible and natural, with slightly different flavours:

a hora de deitar
– Literally “the time to lie down”
– Very commonly used for bedtime, especially in European Portuguese.
– Neutral, slightly concise.
a hora de me deitar
– “the time for me to lie down / to go to bed”
– Makes the subject explicit (me = myself).
– Also perfectly natural.
a hora de ir para a cama
– “the time to go to bed”
– Slightly more descriptive (you’re “going to the bed” rather than just “lying down”).

All three can be used to talk about bedtime. They are largely interchangeable in this sentence.

Why is it “para a cama” and not “para cama”? Do we need the article a here?

In European Portuguese, you normally keep the definite article before nouns like cama, escola, trabalho when you have a preposition:

ir para a cama – go to bed
ir para a escola – go to school
voltar do trabalho – come back from work

So “para a cama” (with a) is the standard form.

Dropping the article (“para cama”) is generally not idiomatic in European Portuguese in this type of expression. In Brazilian Portuguese, articles are sometimes dropped more freely, but “ir para a cama” is still the usual form there as well.

Does “ir para a cama” ever have a sexual meaning, like “go to bed with someone”?

Yes, in some contexts “ir para a cama” can have a sexual meaning:

Ela foi para a cama com ele.
= She went to bed with him (slept with him).

The key is usually the presence of “com alguém” (with someone).

In your sentence:

Se eu respeitar a hora de ir para a cama…

there is no sexual meaning at all. It just means “go to bed (to sleep)”, especially because it is linked to hora, a regular bedtime.

What exactly does “o dia seguinte corre melhor” mean? How does correr get the meaning of “go (better/worse)”?

Here correr doesn’t mean “to run” literally. It’s used in the sense of “to go / to turn out / to unfold”.

O dia seguinte corre melhor.
= The next day goes better / turns out better.

This meaning of correr is very common in Portuguese:

O exame correu bem. – The exam went well.
As coisas correram mal. – Things went badly.
Como é que correu o dia? – How did the day go?

So “corre melhor” means that the experience of the next day is smoother, easier, more pleasant, more productive, etc.

Could we say “o dia seguinte é melhor” instead of “corre melhor”? Would that change the meaning?

You can say “o dia seguinte é melhor”, but the nuance changes slightly:

o dia seguinte corre melhor
– Focuses on how the day unfolds over time.
– Implies things run more smoothly throughout the whole day.
– Very idiomatic, especially with “day”.
o dia seguinte é melhor
– More static: “the next day is better (overall)”.
– Sounds like a general judgement about the day as a whole, not so much about how it goes moment by moment.

Both are understandable, but “corre melhor” is the most natural and expressive in Portuguese for this idea of “the day goes better”.

Why is it “o dia seguinte” and not “no dia seguinte”?

Because in this sentence “o dia seguinte” is the subject of the verb:

o dia seguinte = subject
corre = verb
melhor = complement

If you said “no dia seguinte”, that would be a time expression, not the subject:

No dia seguinte, trabalho melhor.
(On the next day, I work better.)
– Here “no dia seguinte” is like “on the next day”, and “eu” (understood from trabalho) is the subject.

In your sentence, we’re not saying what I do on the next day; we’re saying how the next day itself goes, so “o dia seguinte” is naturally the subject.

Could we drop “eu” and say “Se respeitar a hora de ir para a cama…”? Does that change the meaning?

Grammatically, yes, you can drop “eu”:

Se respeitar a hora de ir para a cama, o dia seguinte corre melhor.

Portuguese is a pro‑drop language, so subject pronouns are often omitted.

However, with the future subjunctive, there is a small ambiguity:

respeitar can be 1st person singular (eu) or 3rd person singular (ele/ela/você).

So without “eu”, the clause could mean:

If I stick to the bedtime…
If he/she/you stick(s) to the bedtime…

Normally, context will make it clear, but many speakers keep the pronoun here (especially with eu) to be more explicit:

Se eu respeitar a hora de ir para a cama, o dia seguinte corre melhor.

Meaning-wise it’s the same; using eu just removes possible ambiguity.