Breakdown of Lo importante es que los mensajes estén encriptados.
ser
to be
estar
to be (location/state)
el mensaje
the message
importante
important
Questions & Answers about Lo importante es que los mensajes estén encriptados.
Why do we use estén instead of sean here?
This is the state passive (pasiva de resultado). We use estar + past participle (estén encriptados) to describe the result or state of an action—the messages are currently in an encrypted state. If we used ser (sean encriptados), it would be the regular passive voice, focusing on the action of the messages being encrypted by someone right now.
Why is estar conjugated in the subjunctive (estén)?
The phrase lo importante es que (the important thing is that) expresses a value judgment, very similar to the impersonal expression es importante que (it is important that). Value judgments like this trigger the subjunctive in the clause that follows them.
Why does encriptados end in -os?
What exactly is lo doing in lo importante?