Acts 18:28

Mightily [ε υ τ ο ν ω ς]. See on Luke 23:10.

Convinced [δ ι α κ α τ η λ ε γ χ ε τ ο]. Only here in New Testament. See on tell him his fault, Matthew 18:15. The compound here is a very strong expression for thorough confutation. Confute (Rev.) is better than convince. Note the prepositions. He confuted them thoroughly [δ ι α], against [κ α τ α] all their arguments.