Irene Heim is a really smart lady who knows a lot about language and how we use it to communicate. She likes to study things called "semantics," which is all about the meanings of words and how we put them together to make sentences that make sense. Think of it like building with Lego bricks: you can put different pieces together to build all kinds of different things, but you have to make sure they fit and make sense.
Irene Heim likes to think about how different words have different meanings depending on how we use them in sentences. For example, the word "bank" could mean a place where you keep your money or the edge of a river. She also thinks about things called "truth conditions," which means figuring out what has to be true for a sentence to be true.
Overall, Irene Heim is really good at studying language and figuring out how we use it to communicate. She helps us understand how we can use words in lots of different ways to say lots of different things.