It might be a stupid question but

Question

I have read and heard these kinds of sentences or utterances many times:

"It might be a stupid question but can fish breath?"

"I don´t know how to say this but you should change your life!"

I don´t understand how to grammatically analyze this correctly. Are these introductory phrases (and therefore a comma has to follow before, "but"!?) followed by a question or an imperative sentence or is a different kind of thing? I can´t make sense of it otherwise because, "This might be a stupid question" can´t really stand by itself for example, can it?

A further question I have is if you have to pose the question or the imperative statement right after, "but". For example:

"It might be a stupid question but it is a question nonetheless: Do fish breath?"

or even

"It might be a stupid question but it is a question I might not pose otherwise. Last year I......and then......(a number of sentences might follow). Do fish breath?"

Answer 1

I think you are basically correct in your understanding. I would rewrite these sentences this way to be more explicit:

This might be a stupid question but I'm going to ask anyway: Do fish breathe?

Note that this is informal speech, also common on the internet, but would not be appropriate in more proper written communication. It's not great grammar.