so if shop keeper ask me do you want to answer some question, and if i say yes how do i print out the question and the answers.

There's two main ways of going about this: Get Input and Show Menu.

For something like this, I think you'll want Get Input. Get Input does exactly that; it has the player type something, and hit enter, and stores the result as a string variable called 'result'. So you can have code like this (Mind my psuedocode):

Get Input{
if result="Yes"{
print("You said yes to the shopkeeper")
}
else if result="Who are you?"{
print("You were confused by the shopkeeper)
}
etc.
}

Show Menu is the best for picking out pre-made options.

Start out with this.

options = Split("item 1; item 2", ";" )
Show Menu ("Shop", options, true) {
  switch (result) {
    case ("item 1" )
      if (player.gold > 10) {
        player.gold = player.gold - 10
        msg ("You bought item 1.")
      }
      else {
        msg ("You don't have enough gold." )
      }
    }
    case ("item 2")
      if (player.gold > 100) {
        player.gold = player.gold -100
        msg ("You bought item 2.")
      }
      else {
        msg ("You don't have enough gold. ")
      }
    }
  }
}

End up with this.

msg ("See something that catches your eye?")
options = Split("Potion (100);Hyper Potion (200);Pistol Fish (360);Ammo (40)", ";")
ShowMenu ("Shop", options, true) {
  switch (result) {
    case ("Potion (100)") {
      if (player.gold >= 100) {
        player.gold = player.gold - 100
        player.potion = player.potion + 1
        msg ("You bought a Potion.")
      }
      else {
        msg ("You don't have enough gold.")
      }
    }
    case ("Hyper Potion (200)") {
      if (player.gold >= 200) {
        player.gold = player.gold - 200
        player.hyper_potion = player.hyper_potion + 1
        msg ("You bought a Hyper Potion.")
      }
      else {
        msg ("You don't have enough gold.")
      }
    }
    case ("Pistol Fish (360)") {
      if (player.gold >= 360) {
        player.gold = player.gold - 360
        AddToInventory (pistol)
      }
      else {
        msg ("Either you don't have enough gold, or you already have it.")
      }
    }
    case ("Ammo (40)") {
      if (player.gold >= 40) {
        player.gold = player.gold - 40
        player.ammo = player.ammo + 20
      }
      else {
        msg ("You don't have enough gold.")
      }
    }
  }
}