Student or Learner
1. How did you create a poll question on FB?
2. How do you create a poll question on FB?
What is the difference between did and do in the sentences above?
In the first instance you are asking a person who has created a poll question on FB. (And presumably knows how to do it.) In the second instance, I can't tell from the way the question is worded it the person has created a poll question on FB or not. You are, presumably, hoping that person knows how to do it, which is why you are asking the question. (I don't know if you can create polls on FB.)