1. Used alone to indicate to someone that what they are doing is not acceptable and that they deserve a warning from you. English = 'I'm warning you!', 'That'll do!', and so on.
2. Often used jokingly in response to being teased or made fun of. English = 'Now, that's enough!', 'Watch it!', 'Don't go too far!', 'You're going too far!', 'Enough is enough!', and so on.
3. Used alone in a friendly way in response to someone saying something which is in complete agreement with what you have already said, when they seem not to realise this. English = "I told you so!", "Didn't I tell you?!" and so on.