John 3:4

When he is old [γ ε ρ ω ν ω ν]. Literally, being an old man.

Can he [μ η δ υ ν α τ α ι]. The interrogative particle anticipates a negative answer. Surely he cannot.

Second time. Nicodemus looks at the subject merely from the physical side. His second time is not the same as Jesus ' anew. As Godet remarks, "he does not understand the difference between a second beginning and a different beginning."