Can you turn a 2x4 into a 4x4?

No, you cannot physically turn a 2x4 into a 4x4 as they are different dimensions. A 2x4 is a piece of lumber that measures approximately 1.5 inches by 3.5 inches, while a 4x4 measures about 3.5 inches by 3.5 inches. You can use multiple 2x4s together to create a structure that functions like a 4x4, but you won't achieve the same dimensions.