Vou remendar a câmara de ar, nem que demore.

In Portuguese, ir + infinitive is a very common way to talk about the future, especially in everyday speech.

So vou remendar means something like I’m going to mend/patch. It sounds natural and conversational.

The simple future, remendarei, is grammatical, but it usually sounds:

• more formal,
• more literary,
• or less common in normal spoken language.

So in ordinary European Portuguese, vou remendar is exactly what you would expect.

Remendar means to mend, to patch, or to fix by patching.

It suggests repairing something by covering or closing a hole, tear, or damaged area. That makes it a very good choice for an inner tube, because you often repair it with a patch.

Compared with other verbs:

• remendar = to patch/mend
• consertar = to fix
• reparar = to repair

So remendar is more specific than consertar or reparar. In this sentence, it gives the idea of a practical, hands-on patch repair.

Câmara de ar is the usual term for an inner tube.

Literally, it is something like air chamber, but you should learn it as a fixed expression meaning inner tube.

There is no article after de because this is a normal noun phrase structure in Portuguese:

• garrafa de água = bottle of water
• máquina de lavar = washing machine
• câmara de ar = inner tube

So de ar does not mean of the air here. It is just part of the set expression.

A is the definite article, so it refers to a specific inner tube: the one the speaker has in mind.

That fits the context well. If someone is dealing with a puncture, both speaker and listener probably know which inner tube is being discussed.

If you said uma câmara de ar, it would sound less specific, more like an inner tube in a general sense.

So:

• a câmara de ar = the inner tube, this particular one
• uma câmara de ar = an inner tube, one inner tube

Not really. In this sentence, nem que should be understood together as a fixed expression.

On its own, nem often means nor or not even, but in nem que + subjunctive, it forms an idiomatic structure meaning something like:

• even if
• no matter if
• even if it takes...

So it is better to treat nem que as one unit here, rather than trying to translate nem separately.

It adds a strong sense of determination.

The speaker is not just saying they will patch the inner tube. They are saying they will do it even if it takes time, even if it is difficult, or whatever it takes.

So the tone is something like:

• I’m going to patch the inner tube, even if it takes a while.
• I’m going to patch the inner tube, no matter how long it takes.

This makes the sentence sound more stubborn, committed, or resolute.

Because nem que is followed by the subjunctive, not the indicative.

Here:

• demora = present indicative
• demore = present subjunctive

After expressions like nem que, Portuguese uses the subjunctive because the action is:

• hypothetical,
• uncertain,
• or presented as a possibility/concession.

So:

• nem que demore = correct
• nem que demora = not standard in this structure

The subject is not stated explicitly, but it is understood from the context.

In practice, the idea is something like:

• even if it takes time
• even if that takes a while
• even if the repair takes a long time

So the hidden subject can be understood as:

• isso,
• o processo,
• arranjar/remendar a câmara de ar as an idea.

Portuguese often leaves this kind of subject unstated when it is obvious from context.

Not very well. A word-for-word translation would sound awkward.

A more natural English rendering depends on the context, for example:

• even if it takes a while
• no matter how long it takes
• even if it takes time
• whatever it takes

This is a good example of a phrase you should understand as a whole, rather than translating each word separately.

Yes, but the nuance may change.

Some possible alternatives are:

• mesmo que demore
  This also means even if it takes a while, but it can sound a little more neutral and less forceful.

• demore o tempo que demorar
  This is very emphatic: however long it takes.

• nem que leve o dia todo
  Even if it takes all day.

So nem que demore is natural and idiomatic, especially when you want to express determination in a compact way.