É necessário abrir todas as janelas durante o dia.

It is necessary to open all the windows during the day.

Breakdown of É necessário abrir todas as janelas durante o dia.

• ser: to be
• o: the
• dia: day
• abrir: to open
• necessário: necessary
• todas as: all the
• janela: window
• durante: during

Questions & Answers about É necessário abrir todas as janelas durante o dia.

Why do we use the infinitive abrir after é necessário instead of a conjugated form like abrimos?

In Portuguese, the construction é necessário + infinitive (literally it is necessary + to + verb) is impersonal. It doesn’t refer to a specific subject who must do the action. Because of this impersonal nature, the verb remains in the infinitive form (abrir) rather than being conjugated.

Could we say É necessário de abrir with de between necessário and abrir?

No. In Portuguese, when we use the structure é necessário, we do not add de before the infinitive. We simply say É necessário abrir.

What is the difference between É necessário abrir todas as janelas and other phrases like É preciso abrir todas as janelas or Tem que abrir todas as janelas?

All of these can convey the same basic meaning of It is necessary to open all the windows. However, é necessário and é preciso sound slightly more formal, while tem que is more colloquial and direct, akin to you have to or you must in English.

Why do we use the definite article as in todas as janelas?

In Portuguese, when we say todas as + [plural noun], we generally include the definite article as. It indicates that we’re referring to all of those specific windows, not just an unspecified group.

Can we replace durante o dia with ao longo do dia?

Yes, you can say ao longo do dia (throughout the day), but it slightly shifts the focus from a general timeframe (during the day) to an ongoing timeframe (throughout the day). Both are correct, but durante o dia is more straightforward and common in everyday speech.