Good Morning How to find if there was any recent changes done to the table structure?
A quick way to check is to query against sys.tables in a database. Every table has a "modify_date" column. That date will either be the create_date if the table has never been modified or it will contain the date of the last ALTER TABLE done.
It won't tell you what the changes are but you can write a pretty simple query to tell you when the last change was. If you write a query to check if there are any modify_date's within the last seven days and write a quick little job that will send you an email when such a date appears, you can have a really good "it just happened" notification system.
If you want to know what the changes actually are, then you'd have to have a system in place to do checks or capture changes like Phil and Grant what have respectively posted about above.