Sparrows will often pop-up briefly before dropping back down out of sight. You'll need to react rapidly to bring the binoculars to your eyes, if you want to get a good enough look for identification before the birds disappear.
It takes practice to be able to I.D. sparrows, as many of them look superficially similar. To start, check bill color, breast markings (streaked or not-streaked), and head patterns. Eventually you'll learn to narrow-down the choices based on various field marks. Don't give up, as sparrows can be wonderfully challenging in Autumn and early Winter!
photo © adrian binns