The phrase "a sort of boy" is correct and usable in written English.
It can be used to describe someone who has qualities or characteristics associated with a boy, but may not fit the traditional definition.
Example: "He was a sort of boy who preferred reading books over playing sports."
Alternatives: "a kind of boy" or "a type of boy".
A sort of boy toy, which was hilarious.
If this photo were a painting by one of the Great Masters it might be called "Allegory of the Popular Fivesome": there was Mr. Rodriguez, from a sort of boy band in the full blossom of popularity, Mr. Fatone from the boy band in middle age, and Ms. Brown from the girl band that is no longer.
I really have a sort of boy's figure".
Over it all floats a larky company of balloonists, whose madcap missions (which include a trip through a hole in the Earth) are the subject of a sort of Boy's Own adventure series, "The Chums of Chance", which in turn forms a framing device for the whole book.
And, of course, he is Lord Voldemort in some movies about a sort of boy magician or what not.
He is also known for his wickedly funny asides, like "The best research for playing a drunk is being a British actor for 20 years" and "I'm a sort of boy next door.
Back on social media, the search quickly becomes a sort of boy-meets-girl version of that wretched dress everyone saw as different colours.
Anyway, Ms. Beckham rewarded us with one of her best collections, which she described as a sort of boy-meets-girl affair.
While the tried-and-true spiritual leaders of the 1980's, like Dr. Wayne Dyre of "Your Erroneous Zones" fame, are still drawing the masses on PBS, there is a new breed emerging -- a sort of boy-of-wonders-next-door, and Dr. Pearl is the prototype.
The far-fetched yet controlled plots invite a sort of boys' magazine writing known among reviewers as "page turners".
Over the next several years, Barcott served as an officer in the Marines in places like Iraq and created an inspiring organization called Carolina for Kibera, which offers health services and serves as a sort of boys and girls club for children in the slum.
