regarding a type hierarchy for numbers based on ABCs.)
The :mod:`collections` module has some concrete classes that derive from
-ABCs; these can, of course, be further derived. In addition the
+ABCs; these can, of course, be further derived. In addition, the
:mod:`collections` module has some ABCs that can be used to test whether
-a class or instance provides a particular interface, for example, is it
-hashable or a mapping.
+a class or instance provides a particular interface, for example, if it is
+hashable or if it is a mapping.
This module provides the following class: