Minor typos

source/core/sharded-cluster-architectures.txt

@@ -236,7 +236,7 @@ potential failure scenarios and available resolutions:
 - All members of a replica set become unavailable.
 
   If all members of a replica set within a shard are unavailable, all
-  data held in on that shard is unavailable. However, the data on all
+  data held in that shard is unavailable. However, the data on all
   other shards will remain available, and it's possible to read and
   write data to the other shards. However, your application must be
   able to deal with partial results, and you should investigate the

source/release-notes/2.2.txt

@@ -357,7 +357,7 @@ In version 2.2, collection names cannot:
 
 - contain the ``$``.
 
-- be an empty string (e.g. ``""``).
+- be an empty string (i.e. ``""``).
 
 This change does not affect collections created with now illegal names
 in earlier versions of MongoDB.

source/tutorial/write-a-tumblelog-application-with-django-mongodb-engine.txt

@@ -59,7 +59,7 @@ Respectively, these commands: install the ``virtualenv`` program
 project (named ``myproject``.)
 
 To activate ``myproject`` environment at the system prompt, use the
-following commands:
+following command:
 
 .. code-block:: bash