- For Teachers
You opened this piece, why?
You opened this, why?
you opened this; why?
You opened this. Why?
The last one.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.
Although this could be pronounced differently. "You opened this why?"; "You opened this when?"
"You escaped how?"; "You sent it where?"
Ok. Thanks. Is it grammatically correct to write this as well?
You opened this why?
No offence but according to your profile you are a native English speaker, based in the USA, and you are an academic. If you opened a leaflet and saw "You opened this why?", what would you think about it?
Also, as a native speaker, it's important to make sure that the learners on this forum see correct written English from you. In post #3, you have missed a space after a comma and failed to capitalise the word "I". The learners here will assume that a post written by a native speaker is written correctly, so please double-check your posts are correct before submitting them. It makes life for all of us here much easier!
Remember - correct capitalisation, punctuation and spacing make posts much easier to read.
NOT A TEACHER
I probably have not understood your question correctly, but would it not be better and more natural to ask:
Why did you decide to read this pamphlet?
HAVE A NICE DAY!