
Seem
Impression Sensing
 Seem is used when you sense something but lack confirmation. 
The sky seems cloudy, but I'm not sure if it'll rain.
 Not Certain
 'Seem' implies uncertainty, it doesn't confirm the fact. 
You seem tired, but I might be wrong.
 Observation Based
 Use 'seem' when making judgments based on observations. 
This task seems difficult, given our current resources.