seguro que vs. seguro de que

Travelogue 4.5 has several examples of this and I don't see why one is used rather than the other. Thanks. Here they are:

- Estoy segura que entenderá.

- Estoy segura que se reirá por ello.

- Estoy segura que Rick no está esperando que tomen dos habitaciones del yate.

- estoy segura de que descubrirás muchas cosas sobre ti mismo en este viaje.

- ¿Están seguros de que no son una pareja?

¡Hola Steven-W15!

Thanks for your question!

According to the rules of proper Spanish grammar, estar seguro must always be followed by de que and never by que. This is because you are sure of something (seguro de algo), rather than sure something  ("seguro algo"). 

However, some native Spanish speakers are guilty of the queísmo phenomenon, which involves omitting prepositions like de when they're supposed to come before que. In this particular lesson, the character Mónica speaks using queísmo.

I will check with our Spanish team to see if we can update this lesson - while it's good to be aware that some native speakers will use queísmo, it's always best to practice the proper grammar forms! :)

Thanks again, and our apologies for the confusion here!

Saludos,

Liss