The phrase "validate him" is grammatically correct and can be used in written English.
You can use it when you want to express a recognition or affirmation of someone's feelings, actions, beliefs, etc. For example: "I decided to validate him for his hard work instead of correcting his mistakes."
Coughlin instead talked up Manning, saying a second Super Bowl victory would validate him as a player and cap his impressive 2011 season.
For Mr. Romney, the choice has quickly helped to validate him in the eyes of skeptical Tea Party members in the House.
For Romney, the decision to pick Mr. Ryan has quickly helped to validate him in the eyes of skeptical Tea Party members in the House.
For D'Antoni, the next two postseasons will validate him as a championship coach or define him as a well-compensated carnival master whose teams are entertaining but lack the weight to win an N.B.A. championship.
John, the WWE's longtime superhero who gets booed by the smarks, needs Daniel to validate him with the smarks.
Still, he's not ashamed of himself, as he used to be: Karen validates him.
Becker won Wimbledon again in 1986, a championship that validated him.
Many, including Sports Illustrated's Lee Jenkins, have argued that Stern, and the NBA in general, have not only failed to appropriately rein in Sterling, but have essentially rewarded him: Sterling was a racist before the Paul trade, and he'd have remained one regardless, but the NBA validated him.
The loudest ovation was reserved for the last player called, LeBron James, who was the subject of national scorn after he left the Cleveland Cavaliers for South Beach but whose performance, and leadership, in leading the Heat to the title last spring has validated him as more than just an individual talent.
