diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index dbaee75..e96ba81 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -42,7 +42,7 @@
          exclude=0, single=0, randomize=0):
     """Execute a test suite.
 
-    This also parses command-line options and modifies its behaviour
+    This also parses command-line options and modifies its behavior
     accordingly. 
 
     tests -- a list of strings containing test names (optional)
diff --git a/Lib/test/test_imageop.py b/Lib/test/test_imageop.py
index 63ab138..6b144c6 100755
--- a/Lib/test/test_imageop.py
+++ b/Lib/test/test_imageop.py
@@ -62,7 +62,7 @@
     image = imageop.grey2rgb(greyimage, width, height)
     
     # Convert a 8-bit deep greyscale image to a 1-bit deep image by
-    # tresholding all the pixels. The resulting image is tightly packed
+    # thresholding all the pixels. The resulting image is tightly packed
     # and is probably only useful as an argument to mono2grey. 
     if verbose:
         print 'grey2mono'
diff --git a/Lib/test/test_pty.py b/Lib/test/test_pty.py
index d6dd1d7..389d2a7 100644
--- a/Lib/test/test_pty.py
+++ b/Lib/test/test_pty.py
@@ -66,7 +66,7 @@
         pass
     except:
         # We don't want this error to propagate, escape the call to
-        # os._exit(), and cause very peculiar behaviour in the calling
+        # os._exit(), and cause very peculiar behavior in the calling
         # regrtest.py !
         debug("Some other error was raised.")
         os._exit(1)
diff --git a/Lib/test/test_winreg.py b/Lib/test/test_winreg.py
index 0eb798f..18ce7a7 100644
--- a/Lib/test/test_winreg.py
+++ b/Lib/test/test_winreg.py
@@ -58,7 +58,7 @@
 def ReadTestData(root_key):
     # Check we can get default value for this key.
     val = QueryValue(root_key, test_key_name)
-    assert val=="Default value", "Registry didnt give back the correct value"
+    assert val=="Default value", "Registry didn't give back the correct value"
 
     key = OpenKey(root_key, test_key_name)
     # Read the sub-keys
@@ -70,9 +70,9 @@
             data = EnumValue(sub_key, index)
         except EnvironmentError:
             break
-        assert data in test_data, "didnt read back the correct test data."
+        assert data in test_data, "Didn't read back the correct test data"
         index = index + 1
-    assert index==len(test_data), "Didnt read the correct number of items"
+    assert index==len(test_data), "Didn't read the correct number of items"
     # Check I can directly access each item
     for value_name, value_data, value_type in test_data:
         read_val, read_typ = QueryValueEx(sub_key, value_name)