Alright kiddo, so Liberal Intergovernmentalism is like when you and your friends play together and everyone gets a say in what game you want to play, but some friends have more influence than others.
Now imagine this on a bigger scale, like countries working together. Just like how you and your friends would have to agree on a game to play, countries have to agree on things they want to do together, like trading or creating rules for how to treat each other's citizens when they visit each other's countries.
Under liberal intergovernmentalism, the countries that are the most powerful and influential, like the United States or Germany, have a bigger say in the decisions that are made. But even though they have more power, they still have to work with the other countries and try to come up with a plan that everyone can agree on.
This way of working together is considered "liberal" because it's based on the idea that countries should work together to achieve common goals like economic growth or security, but each country still maintains its own independence and sovereignty. So, it's like teamwork, but with everyone having a voice and trying to work together to accomplish a common goal.