How to Fown Upon Something

This just means to have or express an unfavorable opinion of again. For example, we frown upon teenagers smoking because it's not good for their health and they're too young. These days, most people frown upon not wearing a mask in public. And finally, this example sentence, people have always frowned upon burping out loud. It seems a little bit rude. The third expression is very important for you to understand and to know how to use it.