Breakdown of Os alpinistas estão doentes por não terem oxigénio, ou seja, o problema é crítico.
ser
to be
não
not / no
ter
to have
o problema
the problem
Questions & Answers about Os alpinistas estão doentes por não terem oxigénio, ou seja, o problema é crítico.
What exactly does ou seja mean in this sentence, and could I use isto é instead?
ou seja translates to 'in other words' or 'that is to say'. It is used to clarify or rephrase the first part of the sentence. Yes, you could perfectly replace it with isto é here, as both are interchangeable connectors of clarification.
Why is the verb terem in the personal infinitive form here instead of just the regular infinitive ter?
We use the personal infinitive terem because it follows the preposition por and we need to agree with the plural subject, Os alpinistas. The -em ending makes it explicitly clear that they are the ones lacking oxygen.
Why do we use por here instead of a word like porque?
The preposition por followed by an infinitive (like terem) is a common way to express a cause or reason, meaning 'due to' or 'because of'. If you used porque, you would need a normally conjugated verb instead, like porque não têm oxigénio.
Why is não placed between por and terem?