Yes, of course. I'll ignore the law that I actually learned in law school and in the actual practice of litigating contracts for what some guy said on the internet...

There's a reason I brought up the falling apple example. Verbal contracts are enforceable--if they satisfy the same requirements as written contracts. On top of that, the terms of a verbal agreement must be corroborated by other evidence outside of the verbal agreement itself in order to survive litigation--and the trend in the US legal system is to require more supporting evidence.