授業に潜るって英語でなんて言うの？

You are at the university and it's your first term. There are some really good optional courses such as Study Skills, Positive Thinking, Motivation. Your first term is quite light on lectures and so you make a decision to attend some courses just for fun. "Are you doing any optional courses?" "Yes, I'm doing positive Thinking and Study Skills." "Me too!"

We use this when we don’t actually attend or are registered in a class. If you sit in on it, you are giving it a try, or testing if it is what you are looking for. You are not an official student.

▪Hey buddy, is it okay if I join you for class even if I do not get any credits. Join=take part in. This is asking your friend if you can take part in his class. ▪Hey, can I go with you to class? I don't take that class but I just want to sit in on it. This is telling your friend that you do not participate in his class but your want to go hear what it is about and want to go with him.

*Can I sit in your class just for fun. This means that you want to sit in for the class because you want to spend time with your friend not for your academics. For example: Friend: I am off to my Science lesson. You:Can I sit in your class just for fun.

Do you think I will get into trouble if I sat with you in your class today? Would your Professor throw me out if I spent time with you in your class?

Audit means to sit in on something and listen to it for a class. Or in financial terms, audit means to take make sure something was recorded or done properly. For example: I've audited a few classes this semester. Or: This company was audited since their tax information seemed to have been filled incorrectly. "Audit a class."

If you are not meant or dont have to do something then this is said to be 'non compulsary' so a class you don't need to attend is called a 'non compulsary class' If you go to something then you are said to 'attend' you can also simply say 'sit in on the class'