The phrase "a knowledgeable one" is correct and usable in written English.
It can be used to refer to a person who possesses a significant amount of knowledge or expertise in a particular area.
Example: "In our discussion, I appreciated the insights shared by Sarah, as she truly is a knowledgeable one in the field of environmental science."
Alternatives: "an informed individual" or "a well-informed person".
We talk to landscaping companies, trying to find a knowledgeable one that won't butcher the old trees.
I asked Frank Brown, the N.H.L.'s vice president for media relations, and formerly a writer, and a knowledgeable one at that, about the sport, what the highlight had been for him.
An approach that turns the clueless parent into a knowledgeable one is using Parental Intelligence that helps you find meaning in your child's behavior.
Olivo is not content to play the part as a "spitfire"; her arguments with and love for Maria and Maria's brother, Bernardo, stem from real concern and hurt, which makes Anita not only a very sexy woman but a sad and knowledgeable one as well.
At times, "Pops" reads like a defense brief, but a very loving and knowledgeable one.
The reality is that you grow so much with every trip you take -- both as a more travel-savvy person and hopefully a more understanding, cultured, and knowledgeable one as well, as you start piecing together history in the context of your travels.
"He's a good man, and very knowledgeable," one club official said.
The boys are noticeably knowledgeable: one asks, "Should the second sopranos do a hocket?" (A hocket means dividing a syllable glotally into more than one note). Later, Mr. Litton plays two notes and asks, "What interval is that?" The answer is an augmented third.
"That's a great story," says someone who should know, and an inquiring mind asks, "Is it true?" The knowledgeable one just says, "No".
He develops in particular detail the arguments that might be made on behalf of the many and the knowledgeable one respectively.
The catch here is that it is impossible for the average person -- and even difficult for the knowledgeable one, for that matter -- to know whether a hermit crab is a male or a female, but it is never hard to spoof the town's nearby big brother, Atlantic City, and the Miss America Pageant.
