This is a great phrase in spoken English to learn both about language and culture. If someone says, “I’m going to have to put my foot down…” they are basically saying that they are going to make the final decision about something, even when other people don’t agree.
Traditionally, a father would say this kind of thing. That is because usually only the “man of the house” has this type of power.
Imagine that a man’s wife really wants to buy a new car. Her husband might say, “Honey, I’d love to buy you that new car, but we can’t afford it right now. It’s so expensive. I’m sorry, but I’m going to have to put my foot down. We won’t be buying any new cars until next year”
A father might say to his daughter, “You are only 16. I don’t want you coming home after midnight any more. It’s too dangerous and I know the kinds of things that boys your age are thinking. They want you for your body and you are too young for this. I’m going to have to put my foot down about this and say that you must come home every night before midnight until you are at least 18″
It is a bit of an “old fashioned” phrase, but sometimes people still say it, and you will often hear this on popular TV shows and in American movies. Now you will know what it means.
Women could say this phrase, but it’s very uncommon because they traditionally don’t have the power to make these types of final decisions. (SpeakFluentEngl.)