Update compatibility-certification.md

Fixed minor grammar issue

Author: ShannonLeavitt

docs/database-engine/install-windows/compatibility-certification.md

@@ -41,7 +41,7 @@ This is also how SharePoint Server 2016 and SharePoint Server 2019 certify on [!
 ## Managing upgrade risk with Compatibility Certification
 Using Compatibility Certification is a valuable approach to database modernization. By certifying based on compatibility level, developers set the technical requirements for an application to be supported on [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] and [!INCLUDE[ssazure_md](../../includes/ssazure_md.md)], but decouple the application lifecycle from the database platform lifecycle. This allows companies to keep the [!INCLUDE[ssDEnoversion](../../includes/ssdenoversion-md.md)] upgraded as needed by lifecycle policies, as well as leveraging new scalability and performance enhancements that are not code dependant, and connecting applications **maintain their functional status** through upgrades.
 
-The possibility of adversely affecting functionality and performance are the main risk factors for any upgrade. Compatibility Certification represents peace of mind in terms of managing these upgrade risks:
+The possibilities of adversely affecting functionality and performance are the main risk factors for any upgrade. Compatibility Certification represents peace of mind in terms of managing these upgrade risks:
 
 -  In what relates to [!INCLUDE[tsql](../../includes/tsql-md.md)] behavior, any change means that an application needs to be recertified for correctness. However, the [database compatibility level](../../t-sql/statements/alter-database-transact-sql-compatibility-level.md) setting provides backward compatibility with earlier versions of [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] only for the specified database, not for the entire server. Keeping the database compatibility level as-is ensures that existing application queries continue to display the same behavior before and after a [!INCLUDE[ssde_md](../../includes/ssde_md.md)] upgrade. For more information about [!INCLUDE[tsql](../../includes/tsql-md.md)] behavior and compatibility levels, see [Using compatibility levels for backward compatibility](../../t-sql/statements/alter-database-transact-sql-compatibility-level.md#backwardCompat).