Can Apple tell I replaced my screen?

I dropped my iPhone 4s awhile back and completely shattered it so I got it replaced. My volume buttons are stuck and won't budge, its very annoying, the volume changes by itself. When I got the screen fixed my buttons worked just fine! So I know the new screen has nothing to do with that. So would they know? I still have warranty on it.

I will of course not mention it, if that means I get a new one. Unless there's a reason I should. I really just don't wanna pay so much money for stupid buttons. But it bothers me So incredibly much.

They shouldn't, I dropped my iPhone 3GS down the stairs and about 3-4 weeks later half of the screen wouldn't work so I could only use half of it… I took it back to apple and they checked it over- I had to pay £50 because it was there was no warrantee / guarantee (not sure which one) left on it, but they never knew that I had replaced the screen
Hope this helps.

Well if they did then i would just act dumb and suggest you have no idea what they are talking about! I had to take a iphone back that had previously had the screen replaced in the circumstances has you but i never got asked any questions and they replaced it right away. But if they did ask any questions i would have acted dumb.
The way i see it they have to prove you wrong not the other way around.

If the repair actually made physical visible changes to the phone, then yes they would know. Like some people when they repair the iPhone they will pry stuff open and Apple will be able to see where they opened.

Apple will also know if you repaired it with a non-original screen.

If you have done none of this, Apple won't know.