How will the teacher know that the student has been detached to another course?

To identify students detached from a course, select the course on the grid, then click on the button in the top right-hand corner. By ticking the Enrolled students, the list of students appears on the right-hand side of the screen.
To see which students are detached from the course, click on the button at the top right of the list: the same icon appears in the list opposite detached students.
To find out exactly which course a detached student is in, hover your mouse over the icon: the name of the class and the teacher in charge of the student appear in a tooltip.