
Knowledgeable
Expertise Implied
 Using 'knowledgeable' implies a deep understanding, often from experience or study. 
He is highly knowledgeable about renewable energy systems.
 Not Omniscient
 Being knowledgeable doesn't mean knowing everything; it's about a specific area. 
Ask Lara for advice, she's very knowledgeable about gardening.
 Positive Connotation
 'Knowledgeable' usually has a positive connotation, praising someone's informed state. 
Our tour guide was incredibly knowledgeable about the city's history.