The character can pinpoint the location of an invisible creature, or detect an illusion with a visual component.
A character can use
Spot to notice the presence of an invisible creature
. The relevant DCs are reprinted here. If the character beats the DC by 20 or more, he or she can pinpoint the location of the invisible creature, though it still maintains total
concealment from the character (50% miss chance).
Defeat Illusion: The character can automatically detect any illusion with a visual component for what it truly is. No Will save is required, and the character doesn't have to interact with the illusion (but he or she must be able to see it).
Pronounce Unfamiliar Language:
This use of the skill allows a character to repeat the speech of an observed creature, potentially allowing a comrade to translate the speech. It doesn't grant the character any ability to understand the language spoken.