You have a student who is not motivated; this student is always distracting people and not paying attention.

Your students are always using the phone or electronic device; they're not paying attention to the class and are distracted with other stuff.

You have an age gap difference between students; you have a student who is 10 and another who is 50. They seem to be bored in class because the adult is talking about stuff that is not interesting to the 10 yo.

You have a classroom full of students who want to translate everything into Spanish; they block themselves when you don't tell them the translation.