He has not been assigned, as he has been CHOSEN.
Here is an example of how the two can be used differently..
If someone is talking to much and cutting you off in conversation you could tell them to stop. This would be a verbal cue.
A nonverbal cue would be if you seemed uninterested in the conversation and continued giving them weird looks or ignored them.
In both inference and observation, you have to monitor or observe something.
Here's one example, you can build on it:
Sherlock Holmes 'observed' the scene below him.
His 'inference' was based on the evidences given to him.
Here's the definition of both of them...
the action or process of closely observing or monitoring something or someone is called observation.
a conclusion reached on the basis of evidence and reasoning is inference.