If a teacher wants to address a student who is late to class, they might say something pke:

"Hello, I noticed that you're late today. Please make sure to arrive on time for future classes."

Alternatively, the teacher might say:

"Good morning/afternoon, [student's name]. I hope you had a good reason for being late today. Please try to arrive on time from now on."

It's important for teachers to be respectful and understanding, but also to set clear expectations for students' behavior and attendance.