I am also confused as to "ansin" in the meaning of "then". Can somebody explain when it is allowed at all to use it in this context?
Ansin can mean "there, in that place" or "then". Duolingo have taken it to mean "then" in this exercise.
One scenario is where I might be talking to you about my training methods.
Me: "I do some stretches first".
You: "Do you run then?" meaning do I run after having done the stretches.
Another scenario is where you ask a child:
Question: "Do you walk to the shop?"
Follow-on question: "Do you run then?" where you are offering an alternative given that the child doesn't walk.
Does it have to do with time? I think it might mean Do you run (after some other event has occurred)?
Is this to mean "Do you run to there?" or "Do you run at that place?" or both? I'm assuming the second, but you can't be too sure.
Maybe "Rithim ann ach ní rithim ansin"