Update doc/reference/annotations.rst

doc/reference/annotations.rst

@@ -196,7 +196,7 @@ by the object iself.
 .. versionadded : 0.12
     @Discriminator was added
 
-This annotation can to enable deserialization of relations which are polymorphic, but
+This annotation allows deserialization of relations which are polymorphic, but
 where a common base class exists. The ``@Discriminator`` annotation has to be applied
 to the least super type::
 
@@ -466,4 +466,4 @@ Resulting XML:
 
 .. code-block :: xml
 
-    <result name="firstname" value="Adrien"/>
+    <result name="firstname" value="Adrien"/>