Update sql-ref-syntax-qry-select-usedb.md

Author: gatorsmile

docs/sql-ref-syntax-qry-select-usedb.md

@@ -20,8 +20,8 @@ license: |
 ---
 
 ### Description
-`USE` statement is used to set a current database. After a current database is set,
-the unqualified database artifacts such as tables, functions  and views that are 
+`USE` statement is used to set the current database. After the current database is set,
+the unqualified database artifacts such as tables, functions and views that are 
 referenced by SQLs are resolved from the current database. 
 The default database name is 'default'.
 
@@ -35,20 +35,20 @@ USE database_name
 <dl>
   <dt><code><em>database_name</em></code></dt>
   <dd>
-     Name of the database will be used. If the database is not exist an exception will be thrown.
+     Name of the database will be used. If the database does not exist, an exception will be thrown.
   </dd>
 </dl>
 
 ### Example
 {% highlight sql %}
--- Use the 'userdb' which is exist.
+-- Use the 'userdb' which exists.
 USE userdb;
 +---------+--+
 | Result  |
 +---------+--+
 +---------+--+
 
--- Use the 'userdb1' which does't exist
+-- Use the 'userdb1' which doesn't exist
 USE userdb1;
 Error: org.apache.spark.sql.catalyst.analysis.NoSuchDatabaseException: Database 'userdb1' not found;(state=,code=0)
 {% endhighlight %}