This has two different meanings depending on location or social classes. From a higher social class, ‘Proper’ denotes actions appropriate to certain circumstances. For example, ‘Don’t do that, it’s not proper!’ However such a usage is becoming less common.

More common, and common in the north and southwest England. “Proper” is used as an alternative to “very” or “extremely”, something that can give a term extra weight. For example, ‘that meal was proper tasty’ or sometimes ‘that was proper.’