Brazilian Portuguese Grammar

The use of the subjunctive mood in subordinating clauses is also mandatory when the main clause is made up of verb ser + adjectives that express urgency, necessity and relevance + connector que (that), e.g.:

Portuguese	English meaning
É importante que...	It's important that...
É relevante que...	It's relevant that...
É vital que...	It's vital that...
É essencial que...	It's essential that...
É necessário que...	It's necessary that...

Examples:

Verbs in the subjunctive mood have been highlighted in green
Portuguese	English
É importante que chegues às cinco.	It's important that you arrive at five.
Era importante que chegasses às cinco.	It was important that you arrive at five.
Será vital que cheguemos às cinco.	It will be vital that we arrive at five.
Seria necessário que chegasses às cinco.	It would be necessary that you arrive at five.

The subjunctive is also used after the main clauses É proibido que and É permitido que:

Portuguese	English
É proibido que fiquemos lá.	We're not allowed to stay there.
Era proibido que ficássemos lá.	We were not allowed to stay there.
É permitido que fumes aqui.	You're allowed to smoke here.