diff --git a/googleapiclient/errors.py b/googleapiclient/errors.py
index 64853a4..2f7b112 100644
--- a/googleapiclient/errors.py
+++ b/googleapiclient/errors.py
@@ -124,7 +124,7 @@
 
 
 class ResumableUploadError(HttpError):
-    """Error occured during resumable upload."""
+    """Error occurred during resumable upload."""
 
     pass
 
@@ -142,7 +142,7 @@
 
 
 class BatchError(HttpError):
-    """Error occured during batch operations."""
+    """Error occurred during batch operations."""
 
     @util.positional(2)
     def __init__(self, reason, resp=None, content=None):
diff --git a/googleapiclient/http.py b/googleapiclient/http.py
index 4125666..8aec1d5 100644
--- a/googleapiclient/http.py
+++ b/googleapiclient/http.py
@@ -709,7 +709,7 @@
 
     Raises:
       googleapiclient.errors.HttpError if the response was not a 2xx.
-      httplib2.HttpLib2Error if a transport error has occured.
+      httplib2.HttpLib2Error if a transport error has occurred.
     """
         headers = self._headers.copy()
         headers["range"] = "bytes=%d-%d" % (
@@ -860,7 +860,7 @@
 
     Raises:
       googleapiclient.errors.HttpError if the response was not a 2xx.
-      httplib2.HttpLib2Error if a transport error has occured.
+      httplib2.HttpLib2Error if a transport error has occurred.
     """
         if http is None:
             http = self.http
@@ -956,7 +956,7 @@
 
     Raises:
       googleapiclient.errors.HttpError if the response was not a 2xx.
-      httplib2.HttpLib2Error if a transport error has occured.
+      httplib2.HttpLib2Error if a transport error has occurred.
     """
         if http is None:
             http = self.http
@@ -1419,7 +1419,7 @@
       request: list, list of request objects to send.
 
     Raises:
-      httplib2.HttpLib2Error if a transport error has occured.
+      httplib2.HttpLib2Error if a transport error has occurred.
       googleapiclient.errors.BatchError if the response is the wrong format.
     """
         message = MIMEMultipart("mixed")
@@ -1495,7 +1495,7 @@
       None
 
     Raises:
-      httplib2.HttpLib2Error if a transport error has occured.
+      httplib2.HttpLib2Error if a transport error has occurred.
       googleapiclient.errors.BatchError if the response is the wrong format.
     """
         # If we have no requests return