Fix grammatical mistake

Author: Tyriar

articles/cost-management-billing/manage/add-change-subscription-administrator.md

@@ -15,7 +15,7 @@ ms.author: banders
 
 To manage access to Azure resources, you must have the appropriate administrator role. Azure has an authorization system called [Azure role-based access control (Azure RBAC)](../../role-based-access-control/overview.md) with several built-in roles you can choose from. You can assign these roles at different scopes, such as management group, subscription, or resource group. By default, the person who creates a new Azure subscription can assign other users administrative access to a subscription.
 
-This article describes how add or change the administrator role for a user using Azure RBAC at the subscription scope. 
+This article describes how to add or change the administrator role for a user using Azure RBAC at the subscription scope. 
 
 This article applies to a Microsoft Online Service Program (pay-as-you-go) account or a Visual Studio account. If you have a Microsoft Customer Agreement (Azure plan) account, see [Understand Microsoft Customer Agreement administrative roles in Azure](understand-mca-roles.md). If you have an Azure Enterprise Agreement, see [Manage Azure Enterprise Agreement roles](understand-ea-roles.md).
 
@@ -64,4 +64,4 @@ If you still need help, [contact support](https://portal.azure.com/?#blade/Micro
 * [What is Azure role-based access control (Azure RBAC)?](../../role-based-access-control/overview.md)
 * [Understand the different roles in Azure](../../role-based-access-control/rbac-and-directory-admin-roles.md)
 * [Associate or add an Azure subscription to your Azure Active Directory tenant](../../active-directory/fundamentals/active-directory-how-subscriptions-associated-directory.md)
-* [Administrator role permissions in Azure Active Directory](../../active-directory/roles/permissions-reference.md)
+* [Administrator role permissions in Azure Active Directory](../../active-directory/roles/permissions-reference.md)