1. Open Transaction SE03
2. Now Select Search for Objects in Requests/Tasks
3. Now, Mention the details as TEXT->press enter, now write the Standard Text that we need to check
Followed and preceded by
<*STANDARD_TEXT_NAME*> and check the Modifiable box to find the modifiable request.
5.Select the check box and hit EXECUTE.We can get the list of the Requests and task.
These are the requests in which your Standard text is locked.