Minor grammatical fix in the schema docs (#1237)

docs/types/schema.rst

@@ -1,11 +1,11 @@
 Schema
 ======
 
-A GraphQL **Schema** defines the types and relationship between **Fields** in your API.
+A GraphQL **Schema** defines the types and relationships between **Fields** in your API.
 
 A Schema is created by supplying the root :ref:`ObjectType` of each operation, query (mandatory), mutation and subscription.
 
-Schema will collect all type definitions related to the root operations and then supplied to the validator and executor.
+Schema will collect all type definitions related to the root operations and then supply them to the validator and executor.
 
 .. code:: python
 
@@ -15,11 +15,11 @@ Schema will collect all type definitions related to the root operations and then
         subscription=MyRootSubscription
     )
 
-A Root Query is just a special :ref:`ObjectType` that :ref:`defines the fields <Scalars>` that are the entrypoint for your API. Root Mutation and Root Subscription are similar to Root Query, but for different operation types:
+A Root Query is just a special :ref:`ObjectType` that :ref:` defines the fields <Scalars>` that are the entrypoint for your API. Root Mutation and Root Subscription are similar to Root Query, but for different operation types:
 
 * Query fetches data
 * Mutation changes data and retrieves the changes
-* Subscription sends changes to clients in real time
+* Subscription sends changes to clients in real-time
 
 Review the `GraphQL documentation on Schema`_ for a brief overview of fields, schema and operations.