aware (knowing about something): We are not aware of the situation.
conscious (knowing or realizing something): I was conscious that someone was watching me.
alert to something (aware of a problem or danger): You must always be alert to the dangers on a busy road.
alive to (aware of, attentive to): You must be more alive to the moods of the others.
mindful (aware, attentive, or careful): You should always be mindful of your surroundings.