Okay, so we're going to talk about a thing called van Wijngaarden grammar, which is a way of writing rules for computer programs to understand how to read and interpret human language (like English or French).
Van Wijngaarden grammar is like a set of instructions that tells the computer how to look at a sentence and figure out what it means. It's kind of like if you were telling your little brother or sister how to put together a puzzle.
For example, if you gave your brother or sister a puzzle with a picture of a dog on it, you might say "Okay, first look for all the pieces with four straight sides. Those are the pieces that go around the outside of the puzzle." And then you might say "Now, look for the pieces with dog fur or a tail on them, those will be the pieces that go in the middle."
Van Wijngaarden grammar is kind of like that. It has rules that tell the computer how to look for different parts of a sentence and put them together in the right way.
For example, it might say "If you see a word that ends in 'ing', that's probably a verb. And if you see a word that comes after 'the' or 'a', that's probably a noun." By following these rules, the computer can figure out what different words in a sentence mean and how they relate to each other.
Overall, van Wijngaarden grammar is a way to help computers understand human language, similar to how you might explain to your little brother or sister how to put together a puzzle.