Field Sparrow has a pink bill and white eye ring.
Swamp Sparrow has rusty wings and a dingy breast.
American Tree Sparrow has a dark breast spot. In Fall and Winter, Chipping Sparrows are quite similar to Clay-colored and Brewer's Sparrows. Often, they retain some rust in the crown and can be identified by that field mark. Clay-colored and Brewer's Sparrows have pale lores and brown rumps. Clay-colored Sparrow has more distinct whisker and a buffier breast.