I'm about to buy my first Honda it is a 2011 Accord that has a hundred and forty thousand miles on it and my brother said something about asking if the timing belt has been changed because it was better to do it before it messed up then after I was wondering how true this is or how I could tell if it had been changed

 

If the 2011 Accord has a 4-Cylinder engine, there is no timing belt, if it has a V6 then there is a 105,000 mile timing belt replacement interval, regardless of mileage.

 

Maybe 105k miles regardless of time?

There isn't a reliable way to tell if it's been changed, other than the seller providing some evidence like a receipt for the work being done.
A belt that's about to break doesn't look all that much different from a belt with only a couple thousand miles on it.

 

Yeah, that! Duh!

This is also true.