Affirmative adverb nai (yes) in the Gospels-Acts

(Translation from NRSV)

Matthew

5: 37Let your word be 'Yes (nai), Yes (nai)' or 'No, No'; anything more than this comes from the evil one.
9: 28When he entered the house, the blind men came to him; and Jesus said to them, "Do you believe that I am able to do this?" They said to him, "Yes (nai), Lord."
11: 9What then did you go out to see? A prophet? Yes (nai), I tell you, and more than a prophet.
11: 26yes (nai), Father, for such was your gracious will.
13: 51"Have you understood all this?" They answered, "Yes (nai)."
15: 27She said, "Yes (nai), Lord, yet even the dogs eat the crumbs that fall from their masters' table."
17: 25He said, "Yes (nai), he does." And when he came home, Jesus spoke of it first, asking, "What do you think, Simon? From whom do kings of the earth take toll or tribute? From their children or from others?"
21: 16and said to him, "Do you hear what these are saying?" Jesus said to them, "Yes (nai); have you never read, 'Out of the mouths of infants and nursing babies you have prepared praise for yourself'?"

Luke

7: 26What then did you go out to see? A prophet? Yes (nai), I tell you, and more than a prophet.
10: 21At that same hour Jesus rejoiced in the Holy Spirit and said, "I thank you, Father, Lord of heaven and earth, because you have hidden these things from the wise and the intelligent and have revealed them to infants; yes (nai), Father, for such was your gracious will.
11: 51from the blood of Abel to the blood of Zechariah, who perished between the altar and the sanctuary. Yes (nai), I tell you, it will be charged against this generation.
12: 5But I will warn you whom to fear: fear him who, after he has killed, has authority to cast into hell. Yes (nai), I tell you, fear him!

John

11: 27She said to him, "Yes (nai), Lord, I believe that you are the Messiah, the Son of God, the one coming into the world."
21: 15When they had finished breakfast, Jesus said to Simon Peter, "Simon son of John, do you love me more than these?" He said to him, "Yes (nai), Lord; you know that I love you." Jesus said to him, "Feed my lambs."
21: 16A second time he said to him, "Simon son of John, do you love me?" He said to him, "Yes (nai), Lord; you know that I love you." Jesus said to him, "Tend my sheep."

Acts

5: 8Peter said to her, "Tell me whether you and your husband sold the land for such and such a price." And she said, "Yes (nai), that was the price."
22: 27The tribune came and asked Paul, "Tell me, are you a Roman citizen?" And he said, "Yes (nai)."