diff --git a/starlette/config.py b/starlette/config.py
index 9a361c4e..68ae7b45 100644
--- a/starlette/config.py
+++ b/starlette/config.py
@@ -23,14 +23,14 @@ class Environ(MutableMapping):
     def __setitem__(self, key: typing.Any, value: typing.Any) -> None:
         if key in self._has_been_read:
             raise EnvironError(
-                f"Attempting to set environ['{key}'], but the value has already be read."
+                f"Attempting to set environ['{key}'], but the value has already been read."
             )
         self._environ.__setitem__(key, value)
 
     def __delitem__(self, key: typing.Any) -> None:
         if key in self._has_been_read:
             raise EnvironError(
-                f"Attempting to delete environ['{key}'], but the value has already be read."
+                f"Attempting to delete environ['{key}'], but the value has already been read."
             )
         self._environ.__delitem__(key)