Breakdown of Estou ciente de que explorar este hospital é ilegal.
ser
to be
de
of / from / by (means of transport) / wearing (attire)
estar
to be (temporary / location)
o hospital
the hospital
Questions & Answers about Estou ciente de que explorar este hospital é ilegal.
Why do we need de right before que?
In English, we say 'aware of' but drop the preposition before 'that' (saying 'aware that'). In Portuguese, the adjective ciente requires the preposition de, and you must keep this preposition even when introducing a clause with que.
Why is the verb é in the indicative rather than the subjunctive?
Why does this sentence use the infinitive explorar instead of a gerund like explorando for 'exploring'?
Could I drop the de in casual speech and just say Estou ciente que...?
You might occasionally hear native speakers drop the de in fast, informal speech, but it is considered grammatically incorrect. To speak correctly, you should always retain the governed preposition before que.